6-K - ERO - Equibles

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 6-K

Report of Foreign Private Issuer

Pursuant to Rule 13a-16 or 15d-16

under the Securities Exchange Act of 1934

For the month of November 2025

Commission File Number 001-40459

ERO COPPER CORP.

(Translation of registrant's name into English)

625 Howe Street, Suite 1050

Vancouver, British Columbia V6C 2T6

Canada

(Address of principal executive office)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F:

Form 20-F ☐ Form 40-F ☒

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1).

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7).

Exhibits 99.1, 99.2 and 99.3 of this Form 6-K is incorporated by reference as an additional exhibit to the registrant’s Registration Statement on Form S-8 (File NO. 333-264821) and Registration Statement on Form F-10 (File NO. 333-274097).

Signatures

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

	Ero Copper Corp.
	By:	/s/ Deepk Hundal
		Name: Deepk Hundal
		Title: EVP, General Counsel and Corporate Secretary
Date: November 4, 2025

Exhibit Index

Exhibit Number	Description of Document
99.1	Management’s Discussion and Analysis for the three and nine months ended September 30, 2025
99.2	Condensed Consolidated Interim Financial Statements for the three and nine months ended September 30, 2025
99.3	Press Release dated November 4 , 2025

Document

MANAGEMENT’S DISCUSSION

AND ANALYSIS

FOR THE THREE AND NINE MONTHS ENDED

SEPTEMBER 30, 2025

1050 – 625 Howe Street, Vancouver, B.C., Canada V6C 2T6

Phone: 604-449-9244 | Website: www.erocopper.com | Email: info@erocopper.com

TABLE OF CONTENTS
BUSINESS OVERVIEW	1
HIGHLIGHTS	2
REVIEW OF OPERATIONS
The Caraíba Operations	6
The Tucumã Operation	7
The Xavantina Operations	8
2025 GUIDANCE	9
REVIEW OF FINANCIAL RESULTS
Review of quarterly results	11
Review of annual results	13
Summary of quarterly results for most recent eight quarters	15
OTHER DISCLOSURES
Liquidity, Capital Resources, and Contractual Obligations	16
Management of Risks and Uncertainties	18
Other Financial Information	22
Accounting Policies, Judgments and Estimates	22
Capital Expenditures	24
Alternative Performance (NON-IFRS) Measures	25
Disclosure Controls and Procedures and Internal Control over Financial Reporting	37
Notes and Cautionary Statements	37

Ero Copper Corp. September 30, 2025 MD&A

MANAGEMENT’S DISCUSSION AND ANALYSIS

This Management’s Discussion and Analysis (“MD&A”) has been prepared as at November 4, 2025 and should be read in conjunction with the unaudited condensed consolidated interim financial statements of Ero Copper Corp. (“Ero”, the “Company”, or “we”) as at, and for the three and nine months ended September 30, 2025, and related notes thereto, which are prepared in accordance with International Accounting Standards (“IAS”) 34, Interim Financial Reporting as issued by the International Accounting Standards Board (the “IASB”). All references in this MD&A to “Q3 2025” and “Q3 2024” are to the three months ended September 30, 2025 and September 30, 2024, respectively, and all references to “YTD 2025” and “YTD 2024” are to the nine months ended September 30, 2025 and September 30, 2024, respectively. This MD&A should be read in conjunction with the Company’s December 31, 2024 audited consolidated financial statements and MD&A. All dollar amounts are expressed in United States (“US”) dollars and tabular amounts are expressed in thousands of US dollars, unless otherwise indicated. References to “$”, “US$”, “dollars”, or “USD” are to US dollars, references to “C$” are to Canadian dollars, and references to “R$” or “BRL” are to Brazilian Reais.

This MD&A refers to various alternative performance (Non-IFRS) measures, including copper C1 cash cost, copper C1 cash cost including foreign exchange hedges, realized copper price, gold C1 cash cost, gold all-in sustaining cost (“AISC”), realized gold price, EBITDA, adjusted EBITDA, adjusted net income attributable to owners of the Company, adjusted net income per share attributable to owners of the Company, net (cash) debt, working capital and available liquidity. Please refer to the section titled "Alternative Performance (Non-IFRS) Measures" for a discussion of non-IFRS measures.

This MD&A contains “forward‐looking statements” that are subject to risk factors set out in a cautionary note contained at the end of this MD&A. The Company cannot assure investors that such statements will prove to be accurate, and actual results and future, events may differ materially from those anticipated in such statements. The results for the periods presented are not necessarily indicative of the results that may be expected for any future period. Investors are cautioned not to place undue reliance on such forward-looking statements. All information contained in this MD&A is current and has been approved by the Board of Directors of the Company (the “Board”) as of November 4, 2025, unless otherwise stated.

BUSINESS OVERVIEW

Ero Copper is a high-margin, high-growth copper producer with operations in Brazil and corporate headquarters in Vancouver, B.C. The Company's primary asset is a 99.6% interest in the Brazilian copper mining company, Mineração Caraíba S.A. ("MCSA"), which is the 100% owner of the Company's Caraíba Operations located in the Curaçá Valley, Bahia State, Brazil and the Tucumã Operation, an open pit copper mine located in Pará State, Brazil. The Company also owns 97.6% of NX Gold S.A. ("NX Gold"), which owns the Xavantina Operations, comprised of an operating gold mine located in Mato Grosso State, Brazil.

Additional information on the Company and its operations, including technical reports on the Caraíba Operations, Xavantina Operations and Tucumã Operation, can be found on SEDAR+ (www.sedarplus.ca) and on EDGAR (www.sec.gov). The Company’s shares are publicly traded on the Toronto Stock Exchange and the New York Stock Exchange under the symbol “ERO”.

Ero Copper Corp. September 30, 2025 MD&A | Page 1

HIGHLIGHTS

Operating Highlights

	2025 - Q3		2025 - Q2		2024 - Q3		2025 - YTD		2024 - YTD
Copper (Caraíba Operations)
Ore Processed (tonnes)	996,661		791,946		900,289		2,481,508		2,711,352
Grade (% Cu)	1.01		1.27		1.20		1.14		1.10
Cu Production (tonnes)	9,085		9,162		9,920		25,604		26,878
Cu Production (lbs)	20,029,832		20,198,967		21,870,631		56,447,924		59,256,602
Cu Sold in Concentrate (tonnes)	9,080		9,387		9,970		25,416		28,137
Cu Sold in Concentrate (lbs)	20,016,537		20,696,749		21,980,217		56,031,397		62,031,124
Cu C1 Cash Cost(1)(2)	$	2.32	$	2.07	$	1.63	$	2.20	$	2.01
Copper (Tucumã Operation)
Ore Processed (tonnes)	575,041		418,699		110,778		1,288,054		110,778
Grade (% Cu)	1.51		1.74		1.00		1.74		1.00
Cu Production (tonnes)	7,579		6,351		839		18,997		839
Cu Production (lbs)	16,707,162		14,002,338		1,850,043		41,880,323		1,850,043
Cu Sold in Concentrate (tonnes)	6,622		5,968		357		17,758		357
Cu Sold in Concentrate (lbs)	14,597,738		13,157,666		787,042		39,148,894		787,042
Cu C1 Cash Cost(1)(2)(3)	$	1.62	$	—	$	—	$	1.62	$	—
Total Copper
Cu Production (tonnes)	16,664		15,513		10,759		44,601		27,717
Cu Production (lbs)	36,736,994		34,201,305		23,720,674		98,328,247		61,106,645
Cu Sold in Concentrate (tonnes)	15,702		15,355		10,327		43,174		28,494
Cu Sold in Concentrate (lbs)	34,614,275		33,854,415		22,767,259		95,180,291		62,818,166
Cu C1 Cash Cost(1)(2)(3)	$	2.00	$	2.07	$	1.63	$	2.07	$	2.01
Gold (Xavantina Operations)
Ore Processed (tonnes)	47,865		37,829		41,761		118,922		120,041
Grade (g / tonne)	8.15		7.11		11.41		7.46		13.85
Au Production (oz)	9,073		7,743		13,485		23,454		48,274
Au Sold (oz)	8,439		8,276		14,615		22,549		49,089
Au C1 Cash Cost(1)	$	1,086	$	1,115	$	539	$	1,100	$	447
Au AISC(1)	$	2,425	$	2,234	$	1,034	$	2,307	$	879

(1) Please refer to the section titled "Alternative Performance (Non-IFRS) Measures" within this MD&A.

(2) Copper C1 cash cost including foreign exchange hedges was $2.25 in Q3 2025 (Q3 2024 - $1.72) and $2.21 in YTD 2025 (YTD 2024 - $2.04) for the Caraíba Operations, and $1.58 in Q3 2025 and $1.58 in YTD 2025 for the Tucumã Operation.

(3) The Company declared commercial production at the Tucumã Operation effective July 1, 2025. As such, YTD 2025 copper C1 cash cost for the Tucumã Operation reflects costs from Q3 2025 onward only. Total YTD 2025 copper C1 cash costs include the Caraíba Operations' YTD costs and Tucumã Operation costs from Q3 2025 onwards.

Ero Copper Corp. September 30, 2025 MD&A | Page 2

Financial Highlights

($ in millions, except per share amounts)

	2025 - Q3		2025 - Q2		2024 - Q3		2025 - YTD		2024 - YTD
Revenues	$	177.1	$	163.5	$	124.8	$	465.7	$	347.7
Gross profit	57.4		67.3		53.7		180.2		128.2
EBITDA(1)	90.8		114.2		74.5		322.8		56.1
Adjusted EBITDA(1)	77.1		82.7		62.2		223.0		157.0
Cash flow from operations	110.3		90.3		52.7		266.0		84.6
Net income (loss)	36.5		71.0		41.4		188.2		(18.9)
Net income (loss) attributable to owners of the Company	36.0		70.5		40.9		186.8		(19.5)
- Per share (basic)	0.35		0.68		0.40		1.80		(0.19)
- Per share (diluted)	0.35		0.68		0.39		1.80		(0.19)
Adjusted net income attributable to owners of the Company(1)	27.9		48.1		27.6		111.9		63.0
- Per share (basic)	0.27		0.46		0.27		1.08		0.61
- Per share (diluted)	0.27		0.46		0.27		1.08		0.61
Cash, cash equivalents, and short-term investments	66.3		68.3		20.2		66.3		20.2
Working deficit(1)	(45.2)		(33.5)		(60.9)		(45.2)		(60.9)
Available liquidity(1)	111.3		113.3		125.2		111.3		125.2
Net debt(1)	545.5		559.1		518.7		545.5		518.7

(1) Please refer to the section titled "Alternative Performance (Non-IFRS) Measures" within this MD&A.

Q3 2025 Highlights

Consolidated copper production increased sequentially, driven by consistent performance at the Caraíba Operation and the continued ramp-up of the Tucumã Operation, while gold production increased quarter-on-quarter as the Xavantina Operations continued to benefit from the transition to mechanized mining.

•Consolidated copper production grew to a record 16,664 tonnes in concentrate at a blended C1 cash cost(1) of $2.00 per pound in Q3 2025, reflecting higher quarter-on-quarter production at Tucumã and consistent quarterly production at Caraíba.

◦The Caraíba Operations produced 9,085 tonnes of copper in concentrate at an average C1 cash cost(1) of $2.32 per pound. Plant throughput reached record quarterly volumes, supported by a multi-quarter plant debottlenecking effort and higher mining rates across all three mines. Overall copper production was steady quarter-on-quarter due to lower planned mined and processed grades. Consequently, C1 cash costs(1) increased 12% compared to the prior period.

◦The Tucumã Operation produced 7,579 tonnes of copper in concentrate at an average C1 cash cost(1) of $1.62 per pound. Production increased 19% from Q2 2025, driven by a 37% increase in throughput as the processing plant continued to ramp up.

Ero Copper Corp. September 30, 2025 MD&A | Page 3

•The Xavantina Operations produced 9,073 ounces of gold at an average C1 cash cost(1) and AISC(1) of $1,086 and $2,425 per ounce, respectively. Gold production increased 17% quarter-on-quarter, with more than 50,000 tonnes mined during the period, the highest quarterly mine volume in more than two years, due to benefits associated with the Company's transition to mechanized mining.

•Quarterly financial performance reflected higher copper concentrate sales at the Tucumã Operation and strengthening copper and gold prices toward the end of the quarter as well as higher operating expenses at Tucumã following the declaration of commercial production on July 1, 2025, as certain ramp-up costs were no longer capitalized, and lower operating margins at the Caraíba Operations due to planned lower mined and processed grades.

◦Net income attributable to the owners of the Company for the quarter was $36.0 million ($0.35 per share on a diluted basis).

◦Adjusted net income attributable to the owners of the Company(1) for the quarter was $27.9 million ($0.27 per share on a diluted basis).

◦Adjusted EBITDA(1) was $77.1 million.

•At quarter-end, available liquidity(1) was $111.3 million, including $66.3 million in cash and cash equivalents and $45.0 million of undrawn availability under the Company's senior secured revolving credit facility ("Senior Credit Facility").

Value-Creation Initiative at Xavantina Significantly Advanced

•The Company launched a value-creation initiative in 2024 aimed at capturing value from stockpiled gold concentrates produced in small but high-grade quantities since processing operations began in 2012. During Q3 2025, these efforts culminated in an initial sales agreement, with shipments commencing in October. The Company expects to sell between 10,000 to 15,000 tonnes at an approximate gold grade of 30 to 40 grams per tonne during Q4 2025, and to complete sampling, shipments, and sales of the remaining volume over the next 12 to 18 months, which is expected to significantly bolster gold sales from the Xavantina Operations.

◦The sales contract for expected 2025 gold concentrate volumes has a net payability, prior to streaming adjustments and after deductions, treatment and refining charges, ranging between 90% and 95% of the prevailing gold price based on the final concentrate grade, port of destination, and the prevailing gold price at the time of sale.

◦Operating costs for excavating, drying, loading, transportation and seaborne freight are expected to be approximately $300 to $500 per ounce.

•Subsequent to quarter-end, the Company published an updated mineral reserve and resource estimate for the Xavantina Operations, which includes a maiden inferred mineral resource estimate for the gold concentrates. The maiden inferred resource estimate contains approximately 29,000 ounces of gold in high-grade, marketable concentrates and is based on sampling of approximately 20% of the total available volume of approximately 60,000 cubic meters. Sampling of the remaining concentrate volume is ongoing. For more information, please refer to the Company’s press release dated November 4, 2025.

Reaffirming 2025 production and capital expenditure guidance; increasing Tucumã cost guidance

•At the Caraíba Operations, copper production is expected to be highest in Q4 2025, driven by higher mined tonnage from the Surubim open pit and increased plant throughput, following

Ero Copper Corp. September 30, 2025 MD&A | Page 4

the successful completion of a multi-quarter debottlenecking program. Full-year copper production and cost guidance ranges are maintained, with production anticipated to be at the low end of the 37,500 to 42,500-tonne range. Full-year C1 cash costs(1) are projected to be within the lower half of the guidance range of $2.15 to $2.35 per pound.

•At the Tucumã Operation, copper production is expected to be highest in Q4 2025, reflecting continued improvements in plant throughput as the Company advances availability improvement initiatives within the tailings filtration circuit. Production in Q4 2025 is also expected to benefit from mine sequencing in higher grade blocks of the open pit. Full-year copper production is expected to be at the low end of the 30,000 to 37,500-tonne guidance range with C1 cash costs(1) now expected to be in the range of $1.35 to $1.55 per pound of copper produced (from $1.10 to $1.30 per pound previously) reflecting higher-than-expected maintenance and freight costs experienced in Q3 2025.

•At the Xavantina Operations, full-year gold production is expected to be toward the lower end of the 40,000 to 50,000-ounce guidance range, with production projected to be highest in Q4 2025 due to higher mined and processed tonnage following the transition to mechanized mining. Full-year C1 cash cost(1) guidance of $850 to $1,000 per ounce and AISC(1) guidance of $1,800 to $2,000 per ounce of gold produced are maintained. In addition, the Company also expects to sell 10,000 to 15,000 tonnes of gold concentrate at an approximate gold grade of 30 to 40 grams per tonne during Q4 2025.

•Full-year capital expenditure guidance remains unchanged at $230 to $270 million.

Furnas Copper-Gold Project ("Furnas" or the "Project"): Phase 1 Drill Program Results Demonstrate High-Grade Continuity and Extend Mineralization; Phase 2 Drill Program Successfully Completed Ahead of Schedule

•During Q3 2025, the Company received full assay results for the 28,000-meter Phase 1 drill program, completed in July. Results from the program continue to demonstrate high-grade continuity throughout the deposit and significantly extend the known limits of mineralization within the high-grade zones (greater than 1% CuEq(2)) to depth. Step-out drilling during Phase 1 extended the known limits of mineralization to approximately 950 meters down-dip from surface, representing a significant increase relative to the Project's National Instrument 43-101 ("NI 43-101") compliant mineral resource estimate, which is based on an average historical depth of drilling of 300 meters (vertical), with a maximum localized down-dip depth from surface of 580 meters.

•Geometallurgical and comminution circuit validation and process improvement testwork, together with the complete Phase 1 assay results, will support a preliminary economic assessment on the Project, including an updated NI 43-101 mineral resource estimate, which the Company plans to publish in H1 2026.

•Subsequent to quarter-end, the Company completed the 17,000-metre Phase 2 drill program at Furnas. The Phase 2 program was completed approximately three months ahead of schedule, and the Company has commenced the Phase 3 drill program with 8 drill rigs currently operating on site.

(1) Please refer to the section titled "Alternative Performance (Non-IFRS) Measures" within this MD&A.

(2) Where applicable, CuEq for Phase 1 of the Furnas Project has been calculated using the following formula: Cu grade + (Au grade x 0.03215 x ($1,900 gold price x 61.50% gold metallurgical recovery / (0.01 x $9,259/tonne copper price x 85.00% copper metallurgical recovery)).

Ero Copper Corp. September 30, 2025 MD&A | Page 5

REVIEW OF OPERATIONS

The Caraíba Operations

	2025 - Q3		2025 - Q2		2024 - Q3		2025 - YTD		2024 - YTD
Ore mined (tonnes)	1,018,972		792,764		874,937		2,507,975		2,560,430
Ore processed (tonnes)	996,661		791,946		900,289		2,481,508		2,711,352
Grade (% Cu)	1.01		1.27		1.20		1.14		1.10
Recovery (%)	90.4		91.1		91.9		90.6		90.2
Cu Production (tonnes)	9,085		9,162		9,920		25,604		26,878
Cu Production (lbs)	20,029,832		20,198,967		21,870,631		56,447,924		59,256,602
Concentrate grade (% Cu)	33.1		32.1		33.3		32.5		33.1
Concentrate sales (tonnes)	27,541		29,365		29,964		78,528		84,907
Cu Sold in concentrate (tonnes)	9,080		9,387		9,970		25,416		28,137
Cu Sold in concentrate (lbs)	20,016,537		20,696,749		21,980,217		56,031,397		62,031,124
Realized copper price(1)	$	4.34	$	4.17	$	3.88	$	4.20	$	3.94
Copper C1 cash cost(1)	$	2.32	$	2.07	$	1.63	$	2.20	$	2.01
Copper C1 cash cost including foreign exchange hedges(1)	$	2.25	$	2.06	$	1.72	$	2.21	$	2.04

(1) Please refer to the section titled "Alternative Performance (Non-IFRS) Measures" within this MD&A.

The Caraíba Operations produced 9,085 tonnes of copper in concentrate during the quarter at an average C1 cash cost(1) of $2.32 per pound of copper produced. Including the impact of allocated foreign exchange hedges, C1 cash costs(1) during the period were $2.25 per pound.

Plant throughput increased 26% compared to Q2 2025, reaching record volumes of nearly 1.0 million tonnes for the period, supported by higher mining rates across all three mines and a successful multi-quarter mill debottlenecking program that enabled increased processing rates. Higher tonnes mined and processed during the period were offset by lower planned grades at both Vermelhos and Pilar. Consequently, C1 cash costs(1) increased 12% quarter-on-quarter.

Full-year copper production from the Caraíba Operations is expected to be at the low end of the 37,500 to 42,500-tonne guidance range, with production anticipated to be highest in Q4 2025, driven by higher mined tonnage from the Surubim open pit and increased plant throughput. C1 cash costs(1) are expected to be within the lower half of the guidance range of $2.15 to $2.35 per pound of copper produced.

Ero Copper Corp. September 30, 2025 MD&A | Page 6

The Tucumã Operation

	2025 - Q3		2025 - Q2		2024 - Q3		2025 - YTD		2024 - YTD
Ore mined (tonnes)	1,333,748		798,811		867,315		2,460,850		867,315
Ore processed (tonnes)	575,041		418,699		110,778		1,288,054		110,778
Grade (% Cu)	1.51		1.74		1.00		1.74		1.00
Recovery (%)	89.2		85.4		75.7		88.0		75.7
Cu Production (tonnes)	7,579		6,351		839		18,997		839
Cu Production (lbs)	16,707,162		14,002,338		1,850,043		41,880,323		1,850,043
Concentrate grade (% Cu)	29.9		30.1		25.5		30.1		25.5
Concentrate sales (tonnes)	24,077		19,468		1,652		59,824		1,652
Cu Sold in concentrate (tonnes)	6,622		5,968		357		17,758		357
Cu Sold in concentrate (lbs)	14,597,738		13,157,666		787,042		39,148,894		787,042
Realized copper price(1)	$	4.22	$	4.04	$	4.19	$	4.12	$	4.19
Copper C1 cash cost(1)(2)	$	1.62	$	—	$	—	$	1.62	$	—
Copper C1 cash cost including foreign exchange hedges(1)(2)	$	1.58	$	—	$	—	$	1.58	$	—

(1) Please refer to the section titled "Alternative Performance (Non-IFRS) Measures" within this MD&A.

(2) The Company declared commercial production at the Tucumã Operation effective July 1, 2025. YTD 2025 copper C1 cash cost and copper C1 cash cost including foreign exchange hedges for the Tucumã Operation refers to the period from Q3 2025 onwards only.

The Tucumã Operation produced 7,579 tonnes of copper in concentrate at an average C1 cash cost(1) of $1.62 per pound during the quarter. The quarter-on-quarter increase in production of 19% was driven by higher plant throughput as processing performance continued to improve through the period, partially offset by lower planned grades. Mining operations continued to perform well with over 1.3 million tonnes of ore mined during the period.

Copper production is expected to be highest in Q4 2025, reflecting a continuation of improvements in plant throughput as the Company advances availability improvement initiatives within the tailings filtration circuit. Production in Q4 2025 is also expected to benefit from mine sequencing in higher grade blocks of the open pit during the quarter. Full-year copper production is expected at the low end of the 30,000 to 37,500-tonne guidance range with C1 cash costs(1) now expected to be in the range of $1.35 to $1.55 per pound of copper produced (from $1.10 to $1.30 per pound previously) reflecting higher-than-expected maintenance and freight costs experienced in Q3 2025.

Ero Copper Corp. September 30, 2025 MD&A | Page 7

The Xavantina Operations

	2025 - Q3		2025 - Q2		2024 - Q3		2025 - YTD		2024 - YTD
Ore mined (tonnes)	50,268		37,829		41,761		121,325		120,041
Ore processed (tonnes)	47,865		37,829		41,761		118,922		120,041
Head grade (grams per tonne Au)	8.15		7.11		11.41		7.46		13.85
Recovery (%)	78.4		88.7		92.5		84.7		91.8
Gold ounces produced (oz)	9,073		7,743		13,485		23,454		48,274
Silver ounces produced (oz)	6,418		4,412		8,168		14,826		28,273
Gold sold (oz)	8,439		8,276		14,615		22,549		49,089
Silver sold (oz)	5,608		5,089		8,523		14,458		28,077
Realized gold price(1)	$	3,280	$	3,114	$	2,382	$	3,070	$	2,156
Gold C1 cash cost(1)	$	1,086	$	1,115	$	539	$	1,100	$	447
Gold AISC(1)	$	2,425	$	2,234	$	1,034	$	2,307	$	879

The Xavantina Operations produced 9,073 ounces of gold during the quarter at a C1 cash cost(1) of $1,086 and an AISC(1) of $2,425 per ounce. Gold production increased 17% quarter-on-quarter, reflecting higher throughput and processed grades as the transition to mechanized mining advanced in several key production areas of Santo Antônio. This resulted in more than 50,000 tonnes of ore mined during the quarter, a mine production rate last achieved in Q2 2022.

Gold recoveries were impacted as the plant experienced thickener overflows and lower-than-expected CIL performance during the period. Process plant modifications were successfully implemented at the end of the quarter to improve operational performance.

As part of a broader effort to unlock additional value from the Xavantina Operations, the Company commenced a value-creation initiative in Q4 2024 aimed at capturing value from stockpiled gold concentrates produced in small but high-grade quantities since processing operations began in 2012. During Q3 2025, these efforts culminated in an initial sales agreement, with shipments commencing in October. The Company expects to sell between 10,000 to 15,000 tonnes at an approximate gold grade of 30 to 40 grams per tonne during Q4 2025, and to complete sampling, shipments, and sales of the remaining volume over the next 12 to 18 months, which is expected to significantly bolster gold sales from the Xavantina Operations.

Full-year production is expected to be toward the lower end of the 40,000 to 50,000-ounce guidance range, with production projected to be highest in Q4 2025 due to higher mined and processed tonnage following the transition to mechanized mining. Full-year C1 cash cost(1) guidance of $850 to $1,000 per ounce of gold produced and AISC(1) guidance of $1,800 to $2,000 per ounce are maintained. In addition, the Company also expects to sell 10,000 to 15,000 tonnes of gold concentrate at an approximate gold grade of 30 to 40 grams per tonne during Q4 2025.

(1) Please refer to the section titled "Alternative Performance (Non-IFRS) Measures" within this MD&A.

Ero Copper Corp. September 30, 2025 MD&A | Page 8

2025 GUIDANCE

Consolidated copper production guidance for 2025 is maintained with overall production expected at the low end of the 67,500 to 80,000 tonne range. Production in Q4 2025 is expected to improve due to increased plant throughput at both the Caraíba and Tucumã Operations, with Tucumã also expected to benefit from mine sequencing in higher grade blocks of the open pit. At the Caraíba Operations C1 cash costs(1) are expected to be in the lower half of the guidance range of $2.15 to $2.35 per pound of copper produced, while at Tucumã C1 cash costs(1) are now expected to be in the $1.35 to $1.55 per pound of copper range from $1.10 to $1.30 per pound of copper previously reflecting higher-than-expected maintenance and freight costs experienced in Q3 2025.

At the Xavantina Operations, gold production is expected to be toward the lower end of the 40,000 to 50,000-ounce guidance range, with production projected to be highest in Q4 2025 due to higher mined and processed tonnage following the transition to mechanized mining. Full-year C1 cash cost(1) guidance of $850 to $1,000 per ounce of gold produced and AISC(1) guidance of $1,800 to $2,000 per ounce are maintained. In addition, the Company also expects to sell 10,000 to 15,000 tonnes of gold concentrate at an approximate gold grade of 30 to 40 grams per tonne during Q4 2025.

2025 Production and Cost Guidance

	Previous Guidance	Current Guidance
Copper Production (tonnes)
Caraíba Operations	37,500 - 42,500	37,500 - 42,500
Tucumã Operation	30,000 - 37,500	30,000 - 37,500
Total Copper	67,500 - 80,000	67,500 - 80,000
Copper C1 Cash Cost(1) Guidance
Caraíba Operations	$2.15 - $2.35	$2.15 - $2.35
Tucumã Operation	$1.10 - $1.30	$1.35 - $1.55
The Xavantina Operations
Au Production (ounces)	40,000 - 50,000	40,000 - 50,000
Gold C1 Cash Cost(1) Guidance	$850 - $1,000	$850 - $1,000
Gold AISC(1) Guidance	$1,800 - $2,000	$1,800 - $2,000

Note: Guidance is based on estimates and assumptions including, but not limited to, mineral reserve estimates, grade and continuity of interpreted geological formations and metallurgical recovery performance. Please refer to the Company’s SEDAR+ and EDGAR filings, including the most recent Annual Information Form ("AIF"), for a detailed summary of risk factors.

(1) Please refer to the section titled "Alternative Performance (Non-IFRS) Measures" within this MD&A.

Ero Copper Corp. September 30, 2025 MD&A | Page 9

2025 Capital Expenditure Guidance

Capital expenditure guidance remains unchanged at a range of $230 to $270 million, excluding capitalized ramp-up costs prior to the declaration of commercial production at the Tucumã Operation.

Figures presented in the table below are in USD millions.

Caraíba Operations	$165 - $180
Tucumã Operation(1)	$30 - $40
Xavantina Operations	$25 - $35
Furnas Copper-Gold Project and Other Exploration	$10 - $15
Total	$230 - $270

(1) Excludes capitalized ramp-up costs prior to the declaration of commercial production at the Tucumã Operation.

Ero Copper Corp. September 30, 2025 MD&A | Page 10

REVIEW OF FINANCIAL RESULTS

The following table provides a summary of the financial results of the Company for Q3 2025 and Q3 2024. Tabular amounts are in thousands of US dollars, except share and per share amounts.

		Three months ended September 30,
	Notes	2025		2024
Revenue	1	$	177,092	$	124,837
Cost of sales	2	(119,695)		(71,128)
Gross profit		57,397		53,709
Expenses
General and administrative		(12,580)		(12,628)
Share-based compensation		(6,742)		(4,859)
Write-down of exploration and evaluation asset		—		(467)
Income before the undernoted		38,075		35,755
Finance income		1,208		781
Finance expense	3	(11,331)		(4,039)
Foreign exchange gain	4	22,055		17,246
Other expenses		(720)		(45)
Income before income taxes		49,287		49,698
Income tax expense
Current		(8,086)		(4,873)
Deferred		(4,688)		(3,458)
	5	(12,774)		(8,331)
Net income for the period		$	36,513	$	41,367
Other comprehensive gain
Foreign currency translation gain	6	22,429		13,757
Comprehensive income		$	58,942	$	55,124
Net income per share attributable to owners of the Company
Basic		$	0.35	$	0.40
Diluted		$	0.35	$	0.39
Weighted average number of common shares outstanding
Basic		103,621,631		103,239,881
Diluted		104,044,755		103,973,827

Ero Copper Corp. September 30, 2025 MD&A | Page 11

Notes:

1. Revenues from copper sales in Q3 2025 was $149.7 million (Q3 2024 - $90.4 million) on sale of 34.6 million lbs of copper (Q3 2024 - 22.8 million lbs). The increase in copper revenues was primarily attributed to $56.0 million of incremental revenue from the Tucumã Operation and a 2% higher average realized price for sales from the Caraíba Operations against the comparative period.

Revenues from gold sales in Q3 2025 was $27.4 million (Q3 2024 - $34.4 million) on sale of 8,439 ounces of gold (Q3 2024 - 14,615 ounces) at an average realized price of $3,280 per ounce (Q3 2024 - $2,382 per ounce). The decrease in gold revenues was primarily driven by 42% lower sales volumes due to reduced head grades, partially offset by a 38% higher realized gold price.

2. Cost of sales for Q3 2025 from copper sales was $104.3 million (Q3 2024 - $59.9 million) which primarily comprised of $25.9 million (Q3 2024 - $16.7 million) in depreciation and depletion, $23.1 million (Q3 2024 - $9.9 million) in contracted services, $19.5 million (Q3 2024 - $13.2 million) in salaries and benefits, $18.0 million (Q3 2024 - $10.0 million) in materials and consumables, $12.4 million (Q3 2024 - $7.3 million) in maintenance costs, $8.7 million (Q3 2024 - $2.4 million) in sales expenses, and $4.6 million (Q3 2024 - $2.2 million) in utilities, partially offset by $9.8 million increase (Q3 2024 - $1.9 million increase) in inventories. The increase in cost of sales in Q3 2025 compared to Q3 2024 was primarily attributed to a $28.9 million increase in cost of sales at the Tucumã Operation upon achieving commercial production on July 1, 2025, as well as a $15.5 million increase at the Caraíba Operations reflecting higher mining and processing cost due to increase in ore mined and processed to offset lower head grade, and $1.0 million incurred on restructuring costs, primarily consisted of severance payments, to optimize headcounts.

Cost of sales for Q3 2025 from gold sales was $15.4 million (Q3 2024 - $11.2 million) which primarily comprised of $5.1 million (Q3 2024 - $4.5 million) in depreciation and depletion, $4.1 million (Q3 2024 - $2.5 million) in salaries and benefits, $2.3 million (Q3 2024 - $1.7 million) in materials and consumables, $2.0 million (Q3 2024 - $2.0 million) in contracted services, $1.3 million (Q3 2024 - $0.7 million) in maintenance costs, and $0.8 million (Q3 2024 - $0.6 million) in utilities, partially offset by $0.6 million increase (Q3 2024 - $1.4 million) in inventories. The increase in cost of sales as compared to Q3 2024 reflects higher mining costs as the operation transitions to mechanized mining, as well as increase in tonnes processed to offset lower head grades.

3. Finance expense for Q3 2025 was $11.3 million (Q3 2024 - $4.0 million) and was primarily comprised of interest on loans and borrowings of $6.7 million (Q3 2024 - nil), accretion of deferred revenue of $2.0 million (Q3 2024 - $0.6 million), other finance expense of $1.0 million (Q3 2024 - $2.4 million), accretion of asset retirement obligations of $0.9 million (Q3 2024 - $0.6 million), and lease interest of $0.7 million (Q3 2024 - $0.5 million). The increase in finance expense from Q3 2024 was primarily due to a decrease in capitalization of borrowing costs after commercial production was achieved at the Tucumã Operation effective July 1, 2025. During the quarter, $4.6 million (Q3 2024 - $9.6 million) in borrowing costs were capitalized to projects in progress primarily related to Deepening project.

4. Foreign exchange gain for Q3 2025 was $22.1 million (Q3 2024 - $17.2 million gain). This amount is primarily comprised of $17.0 million (Q3 2024 - $11.0 million gain) in foreign exchange gain on USD denominated debt at MCSA for which the functional currency is the BRL, $4.0 million (Q3 2024 - $9.8 million gain) of unrealized foreign exchange gain on derivative contracts, and $2.0 million (Q3 2024 - $3.4 million loss) of realized foreign exchange gain on derivative contracts, partially offset by other foreign exchange losses of $1.0 million (Q3 2024 - $0.2 million losses). The unrealized foreign exchange gain on USD denominated debt and on derivative contracts was a result of a 3% strengthening of the BRL against the USD during the period.

5. In Q3 2025, the Company recognized $12.8 million in income tax expense (Q3 2024 $8.3 million expense). The increase in income tax expense was primarily a result of an increase in income before taxes as compared to the same quarter of the prior year.

6. The foreign currency translation gain is a result of a fluctuation of the BRL against the USD during Q3 2025, which strengthened from approximately 5.46 BRL per US dollar at the beginning of Q3 2025 to approximately 5.32 BRL per US dollar by the end of the quarter, when translating the net assets of the Company’s Brazilian subsidiaries to USD for presentation in the Company’s condensed consolidated interim financial statements.

Ero Copper Corp. September 30, 2025 MD&A | Page 12

The following table provides a summary of the financial results of the Company for YTD 2025 and 2024. Tabular amounts are in thousands of US dollars, except share and per share amounts.

		Nine months ended September 30,
	Notes	2025		2024
Revenue	1	$	465,690	$	347,720
Cost of sales	2	(285,485)		(219,542)
Gross profit		180,205		128,178
Expenses
General and administrative		(35,515)		(35,952)
Share-based compensation		(15,671)		(17,479)
Write-down of exploration and evaluation asset	3	—		(11,212)
Income before the undernoted		129,019		63,535
Finance income		3,176		3,610
Finance expense	4	(22,030)		(13,238)
Foreign exchange gain (loss)	5	119,095		(72,204)
Other expenses		(495)		(2,354)
Income (loss) before income taxes		228,765		(20,651)
Income tax (expense) recovery
Current		(21,109)		(11,079)
Deferred		(19,488)		12,868
	6	(40,597)		1,789
Net income (loss) for the period		$	188,168	$	(18,862)
Other comprehensive gain (loss)
Foreign currency translation gain (loss)	7	106,051		(85,881)
Comprehensive income (loss)		$	294,219	$	(104,743)
Net income (loss) per share attributable to owners of the Company
Basic		$	1.80	$	(0.19)
Diluted		$	1.80	$	(0.19)
Weighted average number of common shares outstanding
Basic		103,589,664		103,026,138
Diluted		103,941,295		103,026,138

Ero Copper Corp. September 30, 2025 MD&A | Page 13

Notes:

1. Revenues from copper sales in YTD 2025 amounted to $397.3 million (YTD 2024 - $243.2 million), reflecting the sale of 95.2 million lbs of copper compared to 62.8 million lbs in YTD 2024. The increase in revenues was primarily attributable to ramp-up of production from the Tucumã Operations, which had $155.0 million in revenue compared to $3.1 million in the prior year, as well as realizing higher copper prices at both operations compared to the prior year.

Revenues from gold sales in YTD 2025 was $68.4 million (YTD 2024 - $104.5 million), reflecting the sale of 22,549 ounces of gold at a realized price of $3,070 per ounce, compared to 49,089 ounces of gold sold at a realized price of $2,156 per ounce in YTD 2024. The decrease in revenues was driven by lower sales volume, partially offset by higher gold prices compared to YTD 2024.

2. Cost of sales for YTD 2025 from copper sales was $245.5 million (YTD 2024 - $181.2 million) which primarily consisted of $60.0 million (YTD 2024 - $50.1 million) in depreciation and depletion, $52.5 million (YTD 2024 - $39.5 million) in salaries and benefits, $42.5 million (YTD 2024 - $26.0 million) in contracted services, $39.4 million (YTD 2024 - $28.7 million) in materials and consumables, $33.6 million (YTD 2024 - $21.6 million) in maintenance costs, $16.1 million (YTD 2024 - $6.1 million) in sales expenses, and $11.7 million (YTD 2024 - $7.9 million) in utilities, partially offset by $12.8 million increase (YTD 2024 - $0.6 million decrease) in inventories. The increase in cost of sales was primarily attributable to a $50.4 million increase in cost of sales at the Tucumã Operation upon achieving commercial production on July 1, 2025, as well as a $13.9 million increase at the Caraíba Operations reflecting higher mining and processing cost due to increase in ore mined and processed to offset lower head grade.

Cost of sales for YTD 2025 from gold sales was $40.0 million (YTD 2024- $38.4 million) which primarily comprised of $14.1 million (YTD 2024 - $15.8 million) in depreciation and depletion, $10.0 million (YTD 2024 - $7.6 million) in salaries and benefits, $6.2 million (YTD 2024 - $5.7 million) in contracted services, $5.7 million (YTD 2024 - $5.3 million) in materials and consumables, $2.8 million (YTD 2024 - $1.9 million) in maintenance costs, and $1.9 million (YTD 2024 - $1.8 million) in utilities, partially offset by $2.0 million increase (YTD 2024 - $1.3 million increase) in inventories. The increase in cost of sales reflects higher mining costs as the operation transitions to mechanized mining, as well as increase in tonnes processed to offset lower head grades.

3. In YTD 2024, the Company recognized a write-down in exploration and evaluation assets of $11.2 million, primarily related to the termination of the Fides option agreement.

4. Finance expense for YTD 2025 was $22.0 million (YTD 2024 - $13.2 million) and was primarily comprised of interest on loans and borrowings of $6.7 million (YTD 2024 - nil), other finance expense of $6.1 million (YTD 2024 - $8.2 million) related to expected credit loss provision on a note receivable, accretion of deferred revenue of $4.7 million (YTD 2024 - $1.9 million), accretion of the asset retirement obligations of $2.6 million (YTD 2024 - $1.8 million), and lease interest of $1.9 million (YTD 2024 - $1.4 million). During YTD 2025, $27.0 million (YTD 2024 - $26.1 million) in interest was capitalized to projects in progress. The increase in finance expense was primarily attributable to a decrease in capitalized borrowing costs upon the Tucumã Operation achieving commercial production effective July 1, 2025. The increase in finance expense was also due to higher accretion of deferred revenue driven by the extension of the Original Xavantina Stream at the end of Q1 2025.

5. Foreign exchange gain for YTD 2025 was $119.1 million (YTD 2024 - $72.2 million loss). This amount was primarily comprised of a foreign exchange gain of $95.1 million (YTD 2024 - $56.7 million loss) on USD denominated debt in MCSA, for which the functional currency is the BRL, and a foreign exchange gain on unrealized derivative contracts of $27.4 million (YTD 2024 - $15.6 million loss), and a realized foreign exchange gain on derivative contracts of nominal amount (YTD 2024 - $2.3 million loss), partially offset by other foreign exchange losses of $3.5 million (YTD 2024 - $2.4 million gains). The fluctuation in foreign exchange gains/losses were primarily a result of increased volatility of the USD/BRL foreign exchange rates, where the BRL strengthened 16.4% against the USD during YTD 2025.

6. In YTD 2025, the Company recognized an $40.6 million income tax expense (YTD 2024 - $1.8 million recovery), The change was primarily a result of a net income before income taxes in the current period compared with a net loss before income taxes in the comparative period.

7. The foreign currency translation loss is a result of fluctuations of the BRL against the USD during YTD 2025, which strengthened from approximately 5.74 BRL per US dollar at the beginning of 2025 to approximately 5.32 BRL per US dollar by the end of the quarter, when translating the net assets of the Company’s Brazilian subsidiaries to USD for presentation in the Company’s condensed consolidated interim financial statements.

Ero Copper Corp. September 30, 2025 MD&A | Page 14

SUMMARY OF QUARTERLY RESULTS

The following table presents selected financial information for each of the most recent eight quarters. Tabular amounts are in millions of US Dollars, except share and per share amounts.

Selected Financial Information		Sep. 30,(1)			Jun. 30,(2)			Mar. 31,(3)			Dec. 31,(4)			Sep. 30,(5)			Jun. 30,(6)			Mar. 31,(7)			Dec. 31,(8)
	2025			2025			2025			2024			2024			2024			2024			2023
Revenue		$	177.1		$	163.5		$	125.1		$	122.5		$	124.8		$	117.1		$	105.8		$	116.4
Cost of sales		$	(119.7)		$	(96.2)		$	(69.6)		$	(70.2)		$	(71.1)		$	(73.8)		$	(74.6)		$	(74.6)
Gross profit		$	57.4		$	67.3		$	55.5		$	52.4		$	53.7		$	43.3		$	31.2		$	41.9
Net income (loss) for period		$	36.5		$	71.0		$	80.6		$	(48.9)		$	41.4		$	(53.4)		$	(6.8)		$	37.1
Income (loss) per share attributable to owners of the Company
- Basic		$	0.35		$	0.68		$	0.77		$	(0.47)		$	0.40		$	(0.52)		$	(0.07)		$	0.37
- Diluted		$	0.35		$	0.68		$	0.77		$	(0.47)		$	0.39		$	(0.52)		$	(0.07)		$	0.37
Weighted average number of common shares outstanding
- Basic		103,621,631			103,582,082			103,564,654			103,345,064			103,239,881			103,082,363			102,769,444			98,099,791
- Diluted		104,044,755			103,905,561			103,904,737			103,345,064			103,973,827			103,082,363			102,769,444			98,482,755

Notes:

1.During Q3 2025, the Company recognized net income of $36.5 million compared to net income of $71.0 million in the preceding quarter. The decrease in net income compared to the prior quarter was primarily attributable to a $16.5 million lower foreign exchange gain, $9.9 million lower gross profit and $5.4 million higher finance expense from the cessation of capitalization of borrowing costs at the Tucumã Operation following the declaration of commercial production on July 1, 2025.

2.During Q2 2025, the Company recognized net income of $71.0 million compared to net income of $80.6 million in the preceding quarter. The decrease in net income was primarily attributable to a lower foreign exchange gain of $38.6 million in the current quarter compared to $58.4 million in the preceding quarter, partially offset by a higher gross profit of $67.4 million in the current quarter compared to $55.5 million in the preceding quarter.

3.During Q1 2025, the Company recognized net income of $80.6 million compared to net loss of $48.9 million in the preceding quarter. The increase in net income was primarily attributable to foreign exchange gains of $58.4 million compared to foreign exchange losses of $92.8 million in the preceding quarter, partially offset by an income tax expense of $14.7 million compared to an income tax recovery of $5.9 million in the preceding quarter.

4.During Q4 2024, the Company recognized net loss of $48.9 million compared to net income of $41.4 million in the preceding quarter. The decrease in net income was primarily attributable to foreign exchange losses of $92.8 million compared to foreign exchange gains of $17.2 million in the preceding quarter, partially offset by income tax recovery of $5.9 million compared to income tax expense of $8.3 million in the preceding quarter.

5.During Q3 2024, the Company recognized net income of $41.4 million compared to net loss of $53.4 million in the preceding quarter. The increase in net income was primarily attributable to higher revenues, as well as foreign exchange

Ero Copper Corp. September 30, 2025 MD&A | Page 15

gains of $17.2 million compared to foreign exchange losses of $70.5 million in the preceding quarter, as well as a $10.7 million write-down in exploration and evaluation assets recognized in the preceding quarter.

6.During Q2 2024, the Company recognized net loss of $53.4 million compared to net loss of $6.8 million in the preceding quarter. The increase in loss was primarily attributable to foreign exchange losses of $70.5 million compared to $19.0 million in the preceding quarter. The change in foreign exchange gain or loss was primarily driven by volatility of the Brazilian Real against the US Dollar during the respective periods. In addition, during the quarter, the Company terminated the Fides option agreement, resulting in a write-down in exploration and evaluation assets of $10.7 million.

7.During Q1 2024, the Company recognized net loss of $6.8 million compared to net income of $37.1 million in the preceding quarter. The decrease in income was primarily attributable to foreign exchange losses of $19.0 million compared to foreign exchange gains of $24.9 million in the preceding quarter. The change in foreign exchange gain or loss was primarily driven by volatility of the Brazilian Real against the US Dollar during the respective periods.

8.During Q4 2023, the Company recognized net income of $37.1 million compared to $2.8 million in the preceding quarter. The increase was primarily attributable to foreign exchange gains of $24.9 million compared to foreign exchange losses of $13.9 million in the preceding quarter. The change in foreign exchange gain or loss was primarily driven by volatility of the Brazilian Real against the US Dollar during the respective periods.

LIQUIDITY, CAPITAL RESOURCES, AND CONTRACTUAL OBLIGATIONS

Liquidity

As at September 30, 2025, the Company had cash and cash equivalents of $66.3 million and available liquidity of $111.3 million. Cash and cash equivalents were primarily comprised of cash held with reputable financial institutions and are invested in highly liquid short-term investments with maturities of three months or less. The funds are not exposed to liquidity risk and there are no restrictions on the ability of the Company to use these funds to meet its obligations.

Cash and cash equivalents increased by $15.9 million from December 31, 2024. The Company’s cash flows from operating, investing, and financing activities for the nine months ended September 30, 2025, are summarized as follows:

•Cash from operating activities of $266.0 million, primarily consists of:

◦$223.0 million of adjusted EBITDA (see Non-IFRS Measures); and

◦$50.0 million of advance from the extension of the Original Xavantina Stream;

net of:

◦$8.6 million of amortization of non-cash deferred revenues;

◦$1.6 million of income taxes paid;

◦$1.4 million of net change in non-cash working capital items;

◦$0.5 million of derivative contract settlements; and

◦$1.6 million of income taxes paid.

Ero Copper Corp. September 30, 2025 MD&A | Page 16

•Cash used in investing activities of $205.4 million, including:

◦$192.4 million of additions to mineral property, plant and equipment; and

◦$15.0 million of additions to exploration and evaluation assets;

net of:

◦$2.1 million in proceeds from interest received.

•Cash used in financing activities of $41.4 million, primarily consists of:

◦$57.4 million of new loans and borrowings; and

◦$2.9 million of proceeds from exercise of stock options;

net of:

◦$43.3 million of principal repayments on loans and borrowings;

◦$38.7 million of interest paid on loans and borrowings; and

◦$13.1 million of lease payments.

As at September 30, 2025, the Company had working capital deficit of $45.2 million.

Capital Resources

The Company’s primary sources of capital are comprised of cash from operations, and cash and cash equivalents on hand. The Company continuously monitors its liquidity position and capital structure and, based on changes in operations and economic conditions, may adjust such structure by issuing new common shares or new debt as necessary. Taking into consideration expected cash flow from existing operations and available liquidity, management believes that the Company has sufficient capital to fund its planned operations and activities, and other initiatives, for the foreseeable future.

At September 30, 2025, the Company had available liquidity of $111.3 million, including $66.3 million in cash and cash equivalents and $45.0 million of undrawn availability under its Senior Credit Facility.

In January 2025, the Company amended its Senior Credit Facility to increase the limit from $150.0 million to $200.0 million and to extend the maturity from December 2026 to December 2028. The interest rate and commitment fee on the Credit Facility were reduced to sliding scales of SOFR plus 2.00% to 4.25%, and 0.45% to 0.96%, respectively. Additionally, the total leverage ratio was replaced with net leverage ratio for purposes of determining financial covenants and interest rates.

Ero Copper Corp. September 30, 2025 MD&A | Page 17

In May 2024, to support the commencement of production and associated working capital needs at the Tucumã Operation, the Company entered into a $50.0 million non-priced copper prepayment facility, structured by the Bank of Montreal and with participation by CIBC Capital Markets. This facility is being repaid over 27 equal monthly installments, beginning in October 2024, through the delivery of 272 tonnes of copper each month. Each monthly delivery's value is being determined based on prevailing market copper prices at the time of delivery. Should the value of any delivery exceed the amount of the monthly installment payment of $2.1 million, the excess value will be repaid to the Company. The copper to be delivered by the Company will be in the form of LME Copper Warrants.

In March 2025, the Company exercised its option to increase the size of the non-priced copper prepayment facility by an additional $25.0 million. The Company is obligated to repay the $25.0 million additional facility over 21 equal monthly installments, beginning in April 2025, through the delivery of a minimum of 161 tonnes of copper each month. The copper to be delivered by the Company will be in the form of LME Copper Warrants. Each monthly delivery's value will be determined based on prevailing market copper prices at the time of delivery. Should the value of any delivery exceed the amount of the monthly installment payment of $1.3 million, the excess value will be repaid to the Company.

In relation to its loans and borrowings, the Company is required to comply with certain financial covenants. As of the date of the condensed consolidated interim financial statements, the Company is in compliance with these covenants. The loan agreements also contain covenants that could restrict the ability of the Company and its subsidiaries, including MCSA, Ero Gold, and NX Gold, to, among other things, incur additional indebtedness needed to fund its respective operations, pay dividends or make other distributions, make investments, create liens, sell or transfer assets or enter into transactions with affiliates. There are no other restrictions or externally imposed capital requirements of the Company.

Contractual Obligations and Commitments

The Company has precious metals purchase agreements with a wholly-owned subsidiary of Royal Gold, Inc., whereby the Company is obligated to sell a portion of its gold production from the Xavantina Operations at contract prices.

Refer to the "Liquidity Risk" section for further information on the Company's contractual obligations and commitments.

MANAGEMENT OF RISKS AND UNCERTAINTIES

The Company thoroughly examines the various financial instruments and risks to which it is exposed and assesses the impact and likelihood of those risks. These risks may include credit risk, liquidity risk,

Ero Copper Corp. September 30, 2025 MD&A | Page 18

currency risk, commodity price risk and interest rate risk. Where material, these risks are reviewed and monitored by the Board.

Credit risk

Credit risk is the risk of financial loss to the Company if a customer or counterparty to a financial instrument fails to meet its contractual obligations and arises principally from the Company’s receivables from customers. The carrying amount of the financial assets below represents the maximum credit risk exposure as at September 30, 2025 and December 31, 2024:

	September 30, 2025		December 31, 2024
Cash and cash equivalents	66,257		$	50,402
Accounts receivable	11,132		18,399
Derivatives	9,578		—
Note receivable	13,488		12,009
Deposits and other assets	5,679		4,961
	$	106,134	$	85,771

The Company invests cash and cash equivalents with financial institutions that are financially sound based on their credit rating.

The Company’s exposure to credit risk associated with accounts receivable is influenced mainly by the individual characteristics of each customer.

In 2022, one of the Company's customers in Brazil, Paranapanema S/A ("PMA"), filed for bankruptcy protection. As a preferred supplier to PMA, the Company had a note receivable arrangement with PMA, which was excluded from the judicial recovery process and provides the Company with certain judicial guarantees. According to the note receivable arrangement, repayment was structured over 24 monthly installments beginning in March 2024, with an annual interest rate equivalent to Brazil's CDI rate of approximately 11.65%.

At September 30, 2025, PMA continued to be in default of the agreement and the gross amount of accounts and note receivable from PMA was $25.0 million (December 31, 2024 - $20.7 million). Accordingly, the note receivable is considered credit impaired, and the Company recorded a credit loss provision and present value discount of $15.4 million (December 31, 2024 - $13.1 million). The carrying value of the PMA note receivable at September 30, 2025 was $9.5 million (December 31, 2024 - $7.6 million.), of which $5.3 million (December 31, 2024 - $3.9 million) was included in other current assets.

In the three and nine months ended September 30, 2025, the Company recognized credit loss provisions of nil and $0.2 million (provision of $1.8 million and $6.3 million for the three and nine months ended September 30, 2024) through its profit or loss.

Ero Copper Corp. September 30, 2025 MD&A | Page 19

Liquidity risk

Liquidity risk is the risk associated with the difficulties that the Company may have meeting the obligations associated with financial liabilities that are settled with cash payments or with another financial asset. The Company's approach to liquidity management is to ensure as much as possible that sufficient liquidity exists to meet their maturity obligations on the expiration dates, under normal and stressful conditions, without causing unacceptable losses or with risk of undermining the normal operation of the Company.

The table below shows the Company's maturity of non-derivative financial liabilities on September 30, 2025:

Non-derivative financial liabilities	Carrying <br>value		Contractual cash flows		Up to <br>12 months		1 - 2 <br>years		3 - 5 <br>years		More than <br>5 years
Loans and borrowings (including interest)	$	611,736	$	771,569	$	86,052	$	86,948	$	598,569	$	—
Accounts payable and accrued liabilities	141,941		142,457		142,457		—		—		—
Other non-current liabilities	13,435		25,579		—		24,486		707		386
Leases	26,645		29,479		19,745		8,703		1,011		19
Total	$	793,757	$	969,084	$	248,254	$	120,137	$	600,287	$	405

As at September 30, 2025, the Company has capital commitments, which is net of advances to suppliers, of $45.3 million through contracts and purchase orders which are expected to be incurred over a six-year period. In the normal course of operations, the Company may also enter into long-term contracts which can be cancelled with certain agreed customary notice periods without material penalties.

The Company also has a derivative financial asset for foreign exchange collar contracts whose notional amounts and maturity information are disclosed below under foreign exchange currency risk.

Foreign exchange currency risk

The Company’s subsidiaries in Brazil are exposed to exchange risks primarily related to the US dollar. In order to minimize currency mismatches, the Company monitors its cash flow projections considering future sales expectations indexed to US dollar variation in relation to the cash requirement to settle the existing financings.

The Company's exposure to foreign exchange currency risk at September 30, 2025 relates to $57.8 million (December 31, 2024 – $60.0 million) in loans and borrowings of MCSA denominated in US dollars and Euros. In addition, the Company is also exposed to foreign exchange currency risk at September 30, 2025 on $592.4 million of intercompany loan balances (December 31, 2024 - $513.6 million) which have contractual repayment terms. Strengthening (weakening) in the Brazilian Real against the US dollar at September 30, 2025 by 10% and 20%, would have decreased (increased) pre-tax net loss by $65.0 million and $130.0 million, respectively. This analysis is based on the foreign currency exchange variation rate that the Company considered to be reasonably possible at

Ero Copper Corp. September 30, 2025 MD&A | Page 20

the end of the period and excluding the impact of the derivatives below. The analysis assumes that all other variables, especially interest rates, are held constant.

The Company may use certain foreign exchange derivatives, including collars and forward contracts, to manage its foreign exchange risks. A summary of the Company's foreign exchange derivatives at September 30, 2025 is summarized as follows:

Purpose	Notional Amount	Denomination	Weighted average floor	Weighted average cap / forward price	Maturities
Operational costs	$289.5 million	USD/BRL	5.59	6.59	October 2025 - December 2026
Total	$289.5 million	USD/BRL	5.59	6.59	October 2025 - December 2026

The aggregate fair value of the Company's foreign exchange derivatives was a net asset of $9.6 million (December 31, 2024 - liability of $17.9 million).The fair values of foreign exchange contracts were determined based on option pricing models, forward foreign exchange rates, and information provided by the counter party.

The change in fair value of foreign exchange derivatives was a gain of $4.0 million and a gain of $27.4 million for the three and nine months ended September 30, 2025, respectively (a gain of $9.8 million and a loss of $15.6 million for the three and nine months ended September 30, 2024, respectively), and have been recognized in foreign exchange gain (loss).

In addition, during the three and nine months ended September 30, 2025, the Company recognized a realized gain of $2.0 million and nil, respectively (realized loss of $3.4 million and loss of $2.3 million for the three and nine months ended September 30, 2024 respectively), related to the settlement of foreign currency forward collar contracts.

Interest rate risk

The Company is principally exposed to the variation in interest rates on loans and borrowings with variable rates of interest. Management reduces interest rate risk exposure by entering into loans and borrowings with fixed rates of interest or by entering into derivative instruments that fix the ultimate interest rate paid.

The Company is principally exposed to interest rate risk through its Senior Credit Facility and Brazilian Real denominated bank loans. Based on the Company’s net exposure at September 30, 2025, a 1% change in the variable rates would not materially impact its pre-tax annual net income.

Price risk

The Company may use derivatives, including forward contracts, collars and swap contracts, to manage commodity price risks.

Ero Copper Corp. September 30, 2025 MD&A | Page 21

2025, the fair value of these contracts was a net liability of $3.9 million (December 31, 2024 - liability of $0.1 million). The fair value of gold collar contracts was determined based on option pricing models, forward gold price, and information provided by counter party.

During the three and nine months ended September 30, 2025, the Company recognized an unrealized loss of $1.6 million and loss of $3.1 million (unrealized gain of $0.4 million and nil for the three and nine months ended September 30, 2024), respectively, in relation to its commodity derivatives in other income or loss.

During the three and nine months ended September 30, 2025, the Company recognized a loss of $0.6 million and $0.6 million ($0.8 million and $2.6 million realized loss for three and nine months ended September 30, 2024), respectively, in relation to its commodity derivatives in other income or loss.

At September 30, 2025, the Company had provisionally priced sales that are exposed to commodity price changes. Based on the Company’s net exposure at September 30, 2025, a 10% change in the price of copper would have changed pre-tax net income (loss) by $3.9 million.

For a discussion of additional risks applicable to the Company and its business and operations, including risks related to the Company’s foreign operations, the environment and legal proceedings, see “Risk Factors” in the Company’s AIF.

OTHER FINANCIAL INFORMATION

Off-Balance Sheet Arrangements

As at September 30, 2025, the Company had no material off-balance sheet arrangements.

Outstanding Share Data

As of November 4, 2025, the Company had 103,890,254 common shares issued and outstanding.

ACCOUNTING POLICIES, JUDGMENTS AND ESTIMATES

Critical Accounting Judgments and Estimates

The preparation of condensed consolidated interim financial statements in conformity with IFRS requires management to make judgments, estimates and assumptions about future events that affect the reported amounts of assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the reporting period. Although these estimates are based on management’s best knowledge of the amount, events or actions, actual results may differ from these estimates.

The Company’s material accounting policies and accounting estimates are contained in the Company’s consolidated financial statements for the year ended December 31, 2024 and condensed consolidated interim financial statements for the three and nine months ended September 30, 2025. Judgements have been made in the determination of the functional currency of the Company and its subsidiaries,

Ero Copper Corp. September 30, 2025 MD&A | Page 22

assessment of the probability of cash outflow related to legal claims and contingent liabilities, and commencement of commercial production. Certain of the Company's accounting policies, such as derivative instruments, deferred revenue, carrying amounts of mineral properties, provision for mine closure and reclamation costs, income tax including tax uncertainties, expected credit losses involve critical accounting estimates. Certain of these estimates are dependent on mineral reserves and resource information. Changes in mineral reserves and resources could impact depreciation and depletion rates, asset carrying amounts and the timing of mine closure and reclamation costs. The Company determines its mineral reserves and resources based on information compiled by competent individuals. Information regarding mineral reserves and resources is used in the calculation of depreciation, depletion and determination, when applicable, of the recoverable amount of CGUs, and for forecasting the timing of reclamation and closure cost expenditures. There are numerous uncertainties inherent in the determination of mineral reserves, and assumptions that are valid at the time of determination may change significantly when new information becomes available. Changes in the methodology, forecasted prices of commodities, exchange rates, production costs or recovery rates may change the economic status of mineral reserves and may, ultimately, result in changes in the mineral reserves.

Management continuously reviews its estimates, judgments and assumptions on an ongoing basis using the most current information available. Revisions to estimates are recognized prospectively.

Ero Copper Corp. September 30, 2025 MD&A | Page 23

CAPITAL EXPENDITURES

The following table presents capital expenditures at the Company’s operations on an accrual basis and are net of any sales and value-added taxes.

	2025 - Q3		2025 - Q2		2025 - Q1		2025 - YTD
Caraíba Operations
Growth	$	26,660	$	17,560	$	11,149	$	55,369
Sustaining	28,327		27,135		21,436		76,898
Exploration	2,605		3,325		2,434		8,364
Deposit on Projects	(9,237)		(30)		(615)		(9,882)
Total, Caraíba Operations	$	48,355	$	47,990	$	34,404	$	130,749
Tucumã Project
Growth	90		326		1,160		1,576
Sustaining	6,352		3,087		1,597		11,036
Capitalized ramp-up costs	—		14,016		12,005		26,021
Exploration	112		346		904		1,362
Deposit on Projects	(430)		324		(214)		(320)
Total, Tucumã Project	$	6,124	$	18,099	$	15,452	$	39,675
Xavantina Operations
Sustaining	7,175		4,421		3,904		15,500
Exploration	1,437		1,221		845		3,503
Deposit on Projects	(40)		120		69		149
Total, Xavantina Operations	$	8,572	$	5,762	$	4,818	$	19,152
Corporate and Other
Growth	—		456		293		749
Sustaining	57		5		—		62
Exploration	6,540		4,764		2,642		13,946
Deposit on Projects	95		8		(8)		95
Total, Corporate and Other	$	6,692	$	5,233	$	2,927	$	14,852
Consolidated
Growth	26,750		18,342		12,602		57,694
Sustaining	41,911		34,648		26,937		103,496
Capitalized ramp-up costs	—		14,016		12,005		26,021
Exploration	10,694		9,656		6,825		27,175
Deposit on Projects	(9,612)		422		(768)		(9,958)
Total, Consolidated Capital Expenditures	$	69,743	$	77,084	$	57,601	$	204,428

Ero Copper Corp. September 30, 2025 MD&A | Page 24

	2025 - Q3		2025 - Q2		2025 - Q1		2025 - YTD
Total, Consolidated Capital Expenditures	$	69,743	$	77,084	$	57,601	$	204,428
Add (less):
Additions to exploration and evaluation assets	(6,748)		(5,189)		(3,109)		(15,046)
Additions to right-of-use assets	6,137		6,781		7,175		20,093
Capitalized depreciation	100		114		94		308
Total, additions per Mineral Properties, Plant and Equipment note	$	69,232	$	78,790	$	61,761	$	209,783

ALTERNATIVE PERFORMANCE (NON-IFRS) MEASURES

The Company utilizes certain alternative performance (non-IFRS) measures to monitor its performance, including copper C1 cash cost, copper C1 cash cost including foreign exchange hedges, realized copper price, gold C1 cash cost, gold AISC, realized gold price, EBITDA, adjusted EBITDA, adjusted net income attributable to owners of the Company, adjusted net income per share, net (cash) debt, working capital and available liquidity. These performance measures have no standardized meaning prescribed within generally accepted accounting principles under IFRS and, therefore, amounts presented may not be comparable to similar measures presented by other mining companies. These non-IFRS measures are intended to provide supplemental information and should not be considered in isolation or as a substitute for measures of performance prepared in accordance with IFRS. The tables below provide reconciliations of these non-IFRS measures to the most directly comparable IFRS measures as contained in the Company’s financial statements.

Unless otherwise noted, the non-IFRS measures presented below have been calculated on a consistent basis for the periods presented.

Copper C1 Cash Cost and Copper C1 Cash Cost including Foreign Exchange Hedges

Copper C1 cash cost and copper C1 cash cost including foreign exchange hedges are non-IFRS performance measures used by the Company to manage and evaluate the performance of its copper mining operations.

Copper C1 cash cost is calculated as C1 cash costs divided by total pounds of copper produced during the period. C1 cash costs comprise the total cost of production, including expenses related to transportation, and treatment and refining charges. These costs are net of by-product credits, incentive payments and certain tax credits associated with sales invoiced to the Company's Brazilian customer.

Copper C1 cash cost including foreign exchange hedges is calculated as C1 cash costs, adjusted for realized gains or losses from its operational foreign exchange hedges, divided by total pounds of copper produced during the period. Although the Company does not apply hedge accounting in its consolidated financial statements and recognizes these contracts at fair value through profit or loss, the Company believes it appropriate to present cash costs including the impact of realized gains and losses as these contracts were entered into to mitigate the impact of changes in exchange rates.

While copper C1 cash cost is widely reported in the mining industry as a performance benchmark, it does not have a standardized meaning and is disclosed as a supplement to IFRS measures.

Ero Copper Corp. September 30, 2025 MD&A | Page 25

The following table provides a reconciliation of copper C1 cash cost to cost of production, its most directly comparable IFRS measure.

The Caraíba Operations

Reconciliation:	2025 - Q3		2025 - Q2		2024 - Q3		2025 - YTD		2024 - YTD
Cost of production	$	50,261	$	46,890	$	40,149	$	132,870	$	124,321
Add (less):
Transportation costs & other	1,731		1,792		1,283		4,845		3,818
Treatment, refining, and other	2,508		2,340		3,170		7,258		12,398
By-product credits	(6,693)		(6,205)		(6,584)		(17,597)		(12,455)
Incentive payments	(1,425)		(1,457)		(1,138)		(4,171)		(3,511)
Net change in inventory	199		(1,611)		(1,220)		1,247		(5,581)
Foreign exchange translation and other	(46)		16		3		(177)		17
C1 cash costs	46,535		41,765		35,663		124,275		119,007
Loss (gain) on foreign exchange hedges	(1,460)		(217)		1,965		539		1,735
C1 cash costs including foreign exchange hedges	$	45,075	$	41,548	$	37,628	$	124,814	$	120,742
	2025 - Q3		2025 - Q2		2024 - Q3		2025 - YTD		2024 - YTD
---	---	---	---	---	---	---	---	---	---	---
Costs
Mining	$	33,943	$	31,442	$	26,529	$	91,181	$	79,666
Processing	8,222		6,549		7,069		21,123		22,173
Indirect	8,555		7,639		5,479		22,310		17,225
Production costs	50,720		45,630		39,077		134,614		119,064
By-product credits	(6,693)		(6,205)		(6,584)		(17,597)		(12,455)
Treatment, refining and other	2,508		2,340		3,170		7,258		12,398
C1 cash costs	46,535		41,765		35,663		124,275		119,007
Loss (gain) on foreign exchange hedges	(1,460)		(217)		1,965		539		1,735
C1 cash costs including foreign exchange hedges	$	45,075	$	41,548	$	37,628	$	124,814	$	120,742

Ero Copper Corp. September 30, 2025 MD&A | Page 26

	2025 - Q3		2025 - Q2		2024 - Q3		2025 - YTD		2024 - YTD
Costs per pound
Total copper produced (lbs, 000)	20,030		20,199		21,871		56,448		59,257
Mining	$	1.69	$	1.56	$	1.22	$	1.62	$	1.34
Processing	$	0.41	$	0.32	$	0.32	$	0.37	$	0.38
Indirect	$	0.43	$	0.38	$	0.25	$	0.40	$	0.29
By-product credits	$	(0.33)	$	(0.31)	$	(0.30)	$	(0.31)	$	(0.21)
Treatment, refining and other	$	0.12	$	0.12	$	0.14	$	0.12	$	0.21
Copper C1 cash costs	$	2.32	$	2.07	$	1.63	$	2.20	$	2.01
Loss (gain) on foreign exchange hedges	$	(0.07)	$	(0.01)	$	0.09	$	0.01	$	0.03
Copper C1 cash costs including foreign exchange hedges	$	2.25	$	2.06	$	1.72	$	2.21	$	2.04

The Tucumã Operation(1)

Reconciliation:	2025 - Q3
Cost of production	$	18,308
Add (less):
Transportation costs & other	4,880
Treatment, refining, and other	1,486
Incentive payments	(401)
Net change in inventory	2,783
C1 cash costs	27,056
Loss (gain) on foreign exchange hedges	(586)
C1 cash costs including foreign exchange hedges	$	26,470

(1) The Company declared commercial production at the Tucumã Operation effective July 1, 2025. Tucumã Operation reflects costs from Q3 2025 onward only.

Ero Copper Corp. September 30, 2025 MD&A | Page 27

	2025 - Q3
Costs
Mining	$	4,552
Processing	12,455
Indirect	3,698
Production costs	20,705
Treatment, refining and other	6,351
C1 cash costs	27,056
Loss (gain) on foreign exchange hedges	(586)
C1 cash costs including foreign exchange hedges	$	26,470
	2025 - Q3
---	---	---
Costs per pound
Total copper produced (lbs, 000)	16,707
Mining	$	0.27
Processing	$	0.75
Indirect	$	0.22
Treatment, refining and other	$	0.38
Copper C1 cash costs	$	1.62
Loss (gain) on foreign exchange hedges	$	(0.04)
Copper C1 cash costs including foreign exchange hedges	$	1.58

Ero Copper Corp. September 30, 2025 MD&A | Page 28

Total Copper Operations(1)

Reconciliation:	2025 - Q3		2025 - Q2		2024 - Q3		2025 - YTD		2024 - YTD
Cost of production	$	68,569	$	46,890	$	40,149	$	151,178	$	124,321
Add (less):
Transportation costs & other	6,611		1,792		1,283		9,725		3,818
Treatment, refining, and other	3,994		2,340		3,170		8,744		12,398
By-product credits	(6,693)		(6,205)		(6,584)		(17,597)		(12,455)
Incentive payments	(1,826)		(1,457)		(1,138)		(4,572)		(3,511)
Net change in inventory	2,982		(1,611)		(1,220)		4,030		(5,581)
Foreign exchange translation and other	(46)		16		3		(177)		17
C1 cash costs	73,591		41,765		35,663		151,331		119,007
Loss (gain) on foreign exchange hedges	(2,046)		(217)		1,965		(47)		1,735
C1 cash costs including foreign exchange hedges	$	71,545	$	41,548	$	37,628	$	151,284	$	120,742
	2025 - Q3		2025 - Q2		2024 - Q3		2025 - YTD		2024 - YTD
---	---	---	---	---	---	---	---	---	---	---
Costs
Mining	$	38,495	$	31,442	$	26,529	$	95,733	$	79,666
Processing	20,677		6,549		7,069		33,578		22,173
Indirect	12,253		7,639		5,479		26,008		17,225
Production costs	71,425		45,630		39,077		155,319		119,064
By-product credits	(6,693)		(6,205)		(6,584)		(17,597)		(12,455)
Treatment, refining and other	8,859		2,340		3,170		13,609		12,398
C1 cash costs	73,591		41,765		35,663		151,331		119,007
Loss (gain) on foreign exchange hedges	(2,046)		(217)		1,965		(47)		1,735
C1 cash costs including foreign exchange hedges	$	71,545	$	41,548	$	37,628	$	151,284	$	120,742

(1) Total Copper Operations include Caraíba and Tucumã. The Company declared commercial production at the Tucumã Operation effective July 1, 2025, as such, YTD 2025 copper C1 cash cost for the Tucumã Operation reflects costs from Q3 2025 onward only. Total YTD 2025 copper C1 cash costs and copper C1 cash costs including foreign exchange hedges include the Caraíba Operations' YTD costs and Tucumã Operation costs from Q3 2025 onwards.

Ero Copper Corp. September 30, 2025 MD&A | Page 29

	2025 - Q3		2025 - Q2		2024 - Q3		2025 - YTD		2024 - YTD
Costs per pound
Total copper produced (lbs, 000)	36,737		20,199		21,871		73,155		59,257
Mining	$	1.05	$	1.56	$	1.22	$	1.31	$	1.34
Processing	$	0.56	$	0.32	$	0.32	$	0.46	$	0.38
Indirect	$	0.33	$	0.38	$	0.25	$	0.36	$	0.29
By-product credits	$	(0.18)	$	(0.31)	$	(0.30)	$	(0.24)	$	(0.21)
Treatment, refining and other	$	0.24	$	0.12	$	0.14	$	0.18	$	0.21
Copper C1 cash costs	$	2.00	$	2.07	$	1.63	$	2.07	$	2.01
Loss (gain) on foreign exchange hedges	$	(0.05)	$	(0.01)	$	0.09	$	—	$	0.03
Copper C1 cash costs including foreign exchange hedges	$	1.95	$	2.06	$	1.72	$	2.07	$	2.04

Realized Copper Price

Realized copper price is a non-IFRS ratio which is calculated as gross copper revenue divided by pounds of copper sold during the period. Management believes measuring realized copper price enables investors to better understand performance based on realized copper sales in each reporting period.

The following tables provide a calculation of realized copper price and a reconciliation to copper segment.

The Caraíba Operations

Reconciliation:	2025 - Q3		2025 - Q2		2024 - Q3		2025 - YTD		2024 - YTD
Copper revenue(1)	$	90,598	$	88,404	$	87,305	$	242,272	$	240,104
less: by-product credits	(6,693)		(6,205)		(6,584)		(17,597)		(12,455)
Net copper revenue	83,905		82,199		80,721		224,675		227,649
add: treatment, refining and other	1,388		2,340		3,170		6,138		12,398
add: royalty taxes	1,643		1,695		1,489		4,474		4,276
Gross copper revenue	86,936		86,234		85,380		235,287		244,323
Total copper sold in concentrate (lbs, 000)	20,017		20,697		21,980		56,031		62,031
Realized copper price	$	4.34	$	4.17	$	3.88	$	4.20	$	3.94

(1) Copper revenue includes provisional price and volume adjustments

Ero Copper Corp. September 30, 2025 MD&A | Page 30

The Tucumã Operation

Reconciliation:	2025 - Q3		2025 - Q2		2025 - YTD
Copper revenue(1)	$	59,122	$	49,656	$	155,010
less: by-product credits	553		—		—
Net copper revenue	59,675		49,656		155,010
add: treatment, refining and other	947		2,494		3,520
add: royalty taxes	1,041		1,005		2,902
Gross copper revenue	61,663		53,155		161,432
Total copper sold in concentrate (lbs, 000)	14,598		13,158		39,149
Realized copper price	$	4.22	$	4.04	$	4.12

(1) Copper revenue includes provisional price and volume adjustments

Gold C1 Cash Cost and Gold AISC

Gold C1 cash cost is a non-IFRS performance measure used by the Company to manage and evaluate the operating performance of its gold mining segment and is calculated as C1 cash costs divided by total ounces of gold produced during the period. C1 cash cost includes total cost of production, net of by-product credits and incentive payments. Gold C1 cash cost is widely reported in the mining industry as benchmarks for performance but does not have a standardized meaning and is disclosed in supplemental to IFRS measures.

Gold AISC is an extension of gold C1 cash cost discussed above and is also a key performance measure used by management to evaluate operating performance of its gold mining segment. Gold AISC is calculated as AISC divided by total ounces of gold produced during the period. AISC includes C1 cash costs, site general and administrative costs, accretion of mine closure and rehabilitation provision, sustaining capital expenditures, sustaining leases, and royalties and production taxes. Gold AISC is widely reported in the mining industry as benchmarks for performance but does not have a standardized meaning and is disclosed in supplement to IFRS measures.

The following table provides a reconciliation of gold C1 cash cost and gold AISC to cost of production, its most directly comparable IFRS measure.

Ero Copper Corp. September 30, 2025 MD&A | Page 31

Reconciliation:	2025 - Q3		2025 - Q2		2024 - Q3		2025 - YTD		2024 - YTD
Cost of production	$	10,032	$	8,761	$	6,220	$	25,018	$	21,055
Add (less):
Incentive payments	(364)		(209)		(378)		(842)		(1,047)
Net change in inventory	191		63		1,378		1,593		1,320
By-product credits	(208)		(159)		(232)		(478)		(680)
Smelting and refining	49		42		79		126		266
Foreign exchange translation, transportation and other	156		133		203		373		650
C1 cash costs	$	9,856	$	8,631	$	7,270	$	25,790	$	21,564
Site general and administrative	1,602		1,264		1,321		3,954		4,024
Accretion of mine closure and rehabilitation provision	151		145		82		437		262
Sustaining capital expenditure	7,307		4,435		2,784		15,651		8,691
Sustaining lease payments	2,524		2,313		1,801		6,858		5,831
Royalties and production taxes	566		511		686		1,415		2,058
AISC	$	22,006	$	17,299	$	13,944	$	54,105	$	42,430
	2025 - Q3		2025 - Q2		2024 - Q3		2025 - YTD		2024 - YTD
---	---	---	---	---	---	---	---	---	---	---
Costs
Mining	$	4,871	$	4,552	$	3,852	$	13,183	$	11,377
Processing	2,787		2,472		2,419		7,465		6,955
Indirect	2,357		1,724		1,152		5,494		3,646
Production costs	10,015		8,748		7,423		26,142		21,978
Smelting and refining costs	49		42		79		126		266
By-product credits	(208)		(159)		(232)		(478)		(680)
C1 cash costs	$	9,856	$	8,631	$	7,270	$	25,790	$	21,564
Site general and administrative	1,602		1,264		1,321		3,954		4,024
Accretion of mine closure and rehabilitation provision	151		145		82		437		262
Sustaining capital expenditure	7,307		4,435		2,784		15,651		8,691
Sustaining leases payments	2,524		2,313		1,801		6,858		5,831
Royalties and production taxes	566		511		686		1,415		2,058
AISC	$	22,006	$	17,299	$	13,944	$	54,105	$	42,430

Ero Copper Corp. September 30, 2025 MD&A | Page 32

Costs per ounce
Total gold produced (ounces)	9,073		7,743		13,485		23,454		48,274
Mining	$	537	$	588	$	286	$	562	$	236
Processing	$	307	$	319	$	179	$	318	$	144
Indirect	$	260	$	223	$	85	$	234	$	76
Smelting and refining	$	5	$	5	$	6	$	5	$	6
By-product credits	$	(23)	$	(20)	$	(17)	$	(19)	$	(15)
Gold C1 cash cost	$	1,086	$	1,115	$	539	$	1,100	$	447
Gold AISC	$	2,425	$	2,234	$	1,034	$	2,307	$	879

Realized Gold Price

Realized gold price is a non-IFRS ratio that is calculated as gross gold revenue divided by ounces of gold sold during the period. Management believes measuring realized gold price enables investors to better understand performance based on the realized gold sales in each reporting period. The following table provides a calculation of realized gold price and a reconciliation to gold segment revenues, its most directly comparable IFRS measure.

(in '000s except for ounces and price per ounce)	2025 - Q3		2025 - Q2		2024 - Q3		2025 - YTD		2024 - YTD
Xavantina revenue	$	27,372	$	25,450	$	34,433	$	68,408	$	104,517
less: by-product credits	(208)		(159)		(232)		(478)		(680)
Gold revenue, net	$	27,164	$	25,291	$	34,201	$	67,930	$	103,837
add: smelting, refining, and other charges	520		479		619		1,303		1,985
Gold revenue, gross	$	27,684	$	25,770	$	34,820	$	69,233	$	105,822
Spot (cash)	$	22,342	$	21,132	$	25,718	$	56,228	$	82,022
Stream (cash)	$	2,375	$	1,231	$	2,047	$	4,385	$	5,737
Stream (amortization of deferred revenue)(1)	$	2,967	$	3,407	$	7,055	$	8,620	$	18,063
Total gold ounces sold	8,439		8,276		14,615		22,549		49,089
Spot	6,439		6,394		10,425		17,300		36,508
Stream	2,000		1,882		4,190		5,249		12,581
Realized gold price (per ounce)	$	3,280	$	3,114	$	2,382	$	3,070	$	2,156
Spot	$	3,470	$	3,305	$	2,467	$	3,250	$	2,247
Stream (cash + amortization of deferred revenue)(1)	$	2,672	$	2,464	$	2,172	$	2,477	$	1,892
Cash (spot cash + stream cash)	$	2,929	$	2,702	$	1,900	$	2,688	$	1,788

(1) Amortization of deferred revenue during the three and nine months ended September 30, 2025 was net of nil and $0.5 million (three and nine months ended September 30, 2024 - $1.4 million and $1.2 million, respectively) related to change in estimate attributed to advances received and change in life-of-mine production estimates.

Ero Copper Corp. September 30, 2025 MD&A | Page 33

Earnings before interest, taxes, depreciation, and amortization (“EBITDA”) and Adjusted EBITDA

EBITDA and adjusted EBITDA are non-IFRS performance measures used by management to evaluate its debt service capacity and performance of its operations. EBITDA represents earnings before finance expense, finance income, income taxes, depreciation and amortization. Adjusted EBITDA is EBITDA before the pre-tax effect of adjustments for non-cash and/or non-recurring items required in determination of EBITDA for covenant calculation purposes.

The following table provides a reconciliation of EBITDA and Adjusted EBITDA to net income, its most directly comparable IFRS measure.

Reconciliation:	2025 - Q3		2025 - Q2		2024 - Q3		2025 - YTD		2024 - YTD
Net Income (Loss)	$	36,513	$	71,028	$	41,367	$	188,168	$	(18,862)
Adjustments:
Finance expense	11,331		5,976		4,039		22,030		13,238
Finance income	(1,208)		(1,130)		(781)		(3,176)		(3,610)
Income tax expense (recovery)	12,774		13,082		8,331		40,597		(1,789)
Amortization and depreciation	31,369		25,215		21,555		75,204		67,145
EBITDA	$	90,779	$	114,171	$	74,511	$	322,823	$	56,122
Foreign exchange (gain) loss	(22,055)		(38,640)		(17,246)		(119,095)		72,204
Share based compensation	6,742		7,756		4,859		15,671		17,479
Unrealized loss (gain) on commodity derivatives	1,627		(636)		(360)		3,093		12
Write-down of exploration and evaluation asset	—		—		467		—		11,212
Xavantina Gold Stream transaction fees	—		—		—		458		—
Adjusted EBITDA	$	77,093	$	82,651	$	62,231	$	222,950	$	157,029

(1) Change in rehabilitation and closure provision relates to revisions to rehabilitation and closure plans and cost estimates at the Company’s historic mining operations that have entered the closure phase, and for which there are no substantive future economic value. Such costs are reflected within other expenses on the Company's Consolidated Statements of Operations and Comprehensive (Loss) Income.

Adjusted net income attributable to owners of the Company and Adjusted net income per share attributable to owners of the Company

“Adjusted net income attributable to owners of the Company” is net income attributed to shareholders as reported, adjusted for certain types of transactions that, in management's judgment, are not indicative of our normal operating activities or do not necessarily occur on a recurring basis. “Adjusted net income per share attributable to owners of the Company” (“Adjusted EPS”) is calculated as "adjusted net income attributable to owners of the Company" divided by weighted average number of

Ero Copper Corp. September 30, 2025 MD&A | Page 34

outstanding common shares in the period. The Company believes that, in addition to conventional measures prepared in accordance with IFRS, the Company and certain investor and analysts use these supplemental non-IFRS performance measures to evaluate the normalized performance of the Company. The presentation of Adjusted EPS is not meant to substitute the net income (loss) per share attributable to owners of the Company (“EPS”) presented in accordance with IFRS, but rather it should be evaluated in conjunction with such IFRS measures.

The following table provides a reconciliation of Adjusted net income attributable to owners of the Company and Adjusted EPS to net income attributable to the owners of the Company, its most directly comparable IFRS measure.

Reconciliation:	2025 - Q3		2025 - Q2		2024 - Q3		2025 - YTD		2024 - YTD
Net income (loss) as reported attributable to the owners of the Company	$	35,978	$	70,548	$	40,857	$	186,753	$	(19,531)
Adjustments:
Share based compensation	6,742		7,756		4,859		15,671		17,479
Unrealized foreign exchange (gain) loss on USD denominated balances in MCSA	(15,057)		(28,204)		(11,860)		(82,889)		47,914
Unrealized foreign exchange (gain) loss on foreign exchange derivative contracts	(3,964)		(6,606)		(9,807)		(27,309)		15,503
Unrealized loss (gain) on commodity derivatives	1,574		(633)		(367)		3,020		3
Write-down of exploration and evaluation asset	—		—		465		—		11,210
Xavantina Gold Stream transaction fees	—		—		—		458		—
Tax effect on the above adjustments	2,661		5,281		3,431		16,221		(9,601)
Adjusted net income attributable to owners of the Company	$	27,934	$	48,142	$	27,578	$	111,925	$	62,977
Weighted average number of common shares
Basic	103,621,631		103,582,082		103,239,881		103,589,664		103,026,138
Diluted	104,044,755		103,905,561		103,973,827		103,941,295		103,742,304
Adjusted EPS
Basic	$	0.27	$	0.46	$	0.27	$	1.08	$	0.61
Diluted	$	0.27	$	0.46	$	0.27	$	1.08	$	0.61

Ero Copper Corp. September 30, 2025 MD&A | Page 35

Net Debt

Net debt is a performance measure used by the Company to assess its financial position and ability to pay down its debt. Net debt is determined based on cash and cash equivalents, short-term investments, net of loans and borrowings as reported in the Company’s condensed consolidated interim financial statements. The following table provides a calculation of net (cash) debt based on amounts presented in the Company’s condensed consolidated interim financial statements as at the periods presented.

	September 30, 2025		June 30, 2025		December 31, 2024		September 30, 2024
Current portion of loans and borrowings	$	50,590	$	58,076	$	45,893	$	39,383
Long-term portion of loans and borrowings	561,146		569,300		556,296		499,527
Less:
Cash and cash equivalents	(66,257)		(68,303)		(50,402)		(20,229)
Net debt (cash)	$	545,479	$	559,073	$	551,787	$	518,681

Working Capital and Available Liquidity

Working capital is calculated as current assets less current liabilities as reported in the Company’s condensed consolidated interim financial statements. The Company uses working capital as a measure of the Company’s short-term financial health and ability to meet its current obligations using its current assets. Available liquidity is calculated as the sum of cash and cash equivalents, short-term investments and the undrawn amount available on its revolving credit facilities. The Company uses this information to evaluate the liquid assets available. The following table provides a calculation for these based on amounts presented in the Company’s condensed consolidated interim financial statements as at the periods presented.

	September 30, 2025		June 30, 2025		December 31, 2024		September 30, 2024
Current assets	$	207,413	$	178,524	$	141,790	$	126,808
Less: Current liabilities	(252,579)		(212,010)		(211,706)		(187,708)
Working deficit	$	(45,166)	$	(33,486)	$	(69,916)	$	(60,900)
Cash and cash equivalents	66,257		68,303		50,402		20,229
Available undrawn revolving credit facilities(1)	45,000		45,000		15,000		80,000
Available undrawn prepayment facilities(2)	—		—		25,000		25,000
Available liquidity	$	111,257	$	113,303	$	90,402	$	125,229

(1) In January 2025, the Company amended its Senior Credit Facility to increase the limit from $150.0 million to $200.0 million and extended the maturity from December 2026 to December 2028.

(2) In March 2025, the Company exercised its option to increase the size of its copper prepayment facility from $50.0 million to $75.0 million.

Ero Copper Corp. September 30, 2025 MD&A | Page 36

DISCLOSURE CONTROLS AND PROCEDURES AND INTERNAL CONTROL OVER FINANCIAL REPORTING

The Company’s management, with the participation of the President and CEO and Executive Vice President and CFO, is responsible for establishing and maintaining adequate disclosure controls and procedures (“DC&P”) and internal control over financial reporting (“ICFR”) using Internal Control – Integrated Framework (2013) issued by the Committee of Sponsoring Organizations of the Treadway Commission ("COSO") as its internal control framework.

The Company’s DC&P are designed to provide reasonable assurance that material information related to the Company is identified and communicated on a timely basis.

The Company’s ICFR is a process designed to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with IFRS. Any system of ICFR, no matter how well designed, has inherent limitations and cannot provide absolute assurance that all misstatements and instances of fraud, if any, within the Company have been prevented or detected. The Company’s ICFR is designed to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with IFRS.

There were no changes in the Company’s DC&P and ICFR that materially affected, or are reasonably likely to materially affect, ICFR during the three and nine months ended September 30, 2025.

NOTE REGARDING SCIENTIFIC AND TECHNICAL INFORMATION

Unless otherwise indicated, scientific and technical information in this MD&A relating to Ero’s properties (“Technical Information”) is based on information contained in the following:

The report prepared in accordance with National Instrument 43-101, Standards of Disclosure for Mineral Projects (“NI 43-101”) and entitled “2022 Mineral Resources and Mineral Reserves of the Caraíba Operations, Curaçá Valley, Bahia, Brazil”, dated December 22, 2022 with an effective date of September 30, 2022, prepared by Porfirio Cabaleiro Rodriguez, FAIG, Bernardo Horta de Cerqueira Viana, FAIG, Fábio Valério Câmara Xavier, MAIG and Ednie Rafael Moreira de Carvalho Fernandes, MAIG all of GE21 Consultoria Mineral Ltda. (“GE21”), Dr. Beck Nader, FAIG of BNA Mining Solutions (“BNA”) and Alejandro Sepulveda, Registered Member (#0293) (Chilean Mining Commission) of NCL Ingeniería y Construcción SpA (“NCL”) (the “Caraíba Operations Technical Report”). Each a “qualified person” and “independent” of the Company within the meanings of NI 43-101.

The Company's press release dated November 4, 2025 regarding the updated mineral reserve and resource estimate for the Xavantina Operations or, as applicable, the report prepared in accordance with NI 43-101 and entitled “Technical Report on the Xavantina Operations, Mato Grosso, Brazil”, dated November May 12, 2023 with an effective date of October 31, 2022, prepared by Porfirio Cabaleiro Rodriguez, FAIG, Leonardo de Moraes Soares, MAIG and Guilherme Gomides Ferreira, MAIG, all of GE21 (the “Xavantina Operations Technical Report”), each a “qualified person” and “independent” of the Company within the meanings of NI 43-101.

The report prepared in accordance with NI 43-101 and entitled “Boa Esperança Project NI 43-101 Technical Report on Feasibility Study Update”, dated November 12, 2021 with an effective date of August 31, 2021, prepared by Kevin Murray, P. Eng., Scott C. Elfen, P.E. (each of Ausenco Engineering Canada Inc.), Erin L. Patterson, P.E. (formerly employed by its affiliate Ausenco Engineering USA

Ero Copper Corp. September 30, 2025 MD&A | Page 37

South Inc. and together with Ausenco Engineering Canada Inc., referred to as “Ausenco”), Carlos Guzmán, FAusIMM RM CMC of NCL, and Emerson Ricardo Re, MSc, MBA, MAusIMM (CP) (No. 305892), Registered Member (No. 0138) (Chilean Mining Commission) and Resource Manager of the Company on the date of the report (now of HCM Consultoria Geologica Eireli (“HCM”)) (the “Tucumã Project Technical Report”). Each of Kevin Murray, P. Eng., Erin L. Patterson, P.E., Scott C. Elfen, P.E., Carlos Guzmán, FAusIMM RM CMC and Emerson Ricardo Re, MAusIMM (CP), is a “qualified person” of the Company within the meanings of NI 43-101 or, in the case of Erin L. Patterson, P.E., who is no longer employed by Ausenco, was a "qualified person" of the Company within the meanings of NI 43-101 on the date of the report. Each of Kevin Murray, P. Eng., Erin L. Patterson, P.E., Scott C. Elfen, P.E., and Carlos Guzmán, FAusIMM RM CMC is “independent” of the Company within the meanings of NI 43-101 or, in the case of Erin L. Patterson, P.E., was "independent" of the Company on the date of the report. Emerson Ricardo Re, MAusIMM (CP), as Resource Manager of the Company (on the date of the report and now of HCM), was not “independent” of the Company on the date of the report, within the meaning of NI 43-101.

Reference should be made to the full text of the Caraíba Operations Technical Report, the Xavantina Operations Technical Report and the Tucumã Project Technical Report, each of which is available for review on the Company's website at www.erocopper.com and under the Company’s profile on SEDAR+ at www.sedarplus.ca, and EDGAR at www.sec.gov.

The disclosure of Technical Information in this MD&A has been reviewed and approved by Cid Gonçalves Monteiro Filho, SME RM (04317974), MAIG (No. 8444), FAusIMM (No. 329148) and Mineral Resources and Reserves Manager of the Company who is a “qualified person” within the meanings of NI 43-101.

Cautionary Note Regarding Forward-Looking Statements

This MD&A contains “forward-looking statements” within the meaning of the United States Private Securities Litigation Reform Act of 1995 and “forward-looking information” within the meaning of applicable Canadian securities legislation (collectively, “forward-looking statements”). Forward-looking statements include statements that use forward-looking terminology such as “may”, “could”, “would”, “will”, “should”, “intend”, “target”, “plan”, “expect”, “budget”, “estimate”, “forecast”, “schedule”, “anticipate”, “believe”, “continue”, “potential”, “view” or the negative or grammatical variation thereof or other variations thereof or comparable terminology. Forward-looking statements may include, but are not limited to, statements with respect to the Company’s production, operating cost and capital expenditure guidance; targeting additional mineral resources and expansion of deposits; capital and operating cost estimates and economic analyses (including cash flow projections), including those from the Caraíba Operations Technical Report, the Xavantina Operations Technical Report and the Tucumã Project Technical Report; the Company’s expectations, strategies and plans for the Caraíba Operations, the Xavantina Operations and the Tucumã Operation, including the Company’s planned exploration, development, construction and production activities; the Company's plans for the Furnas Project; the results of future exploration and drilling; estimated completion dates for certain milestones; successfully adding or upgrading mineral resources (including the Company's expectations associated with the stockpiled gold concentrates at the Xavantina Operations) and successfully developing new deposits; the Company's ability to monetize gold concentrates produced at the Xavantina Operations, including the expected tonnes of gold concentrate to be sold and associated grade per tonne; the costs and timing of future exploration, development and construction; the timing and amount of future production at the Caraíba Operations, the Xavantina Operations and the Tucumã Operation; expectations regarding the Company's ability to

Ero Copper Corp. September 30, 2025 MD&A | Page 38

manage risks related to future copper and gold price fluctuations and volatility; future financial or operating performance and condition of the Company and its business, operations and properties, including expectations regarding liquidity, capital structure, competitive position and payment of dividends; expectations regarding future currency exchange rates; expected concentrate treatment and refining charges; gold by-product credits and USD to BRL exchange rate; and any other statement that may predict, forecast, indicate or imply future plans, intentions, levels of activity, results, performance or achievements.

Forward-looking statements are subject to a variety of known and unknown risks, uncertainties and other factors that could cause actual results, actions, events, conditions, performance or achievements to materially differ from those expressed or implied by the forward-looking statements, including, without limitation, risks discussed in this MD&A and in the AIF under the heading “Risk Factors”. The risks discussed in this MD&A and in the AIF are not exhaustive of the factors that may affect any of the Company’s forward-looking statements. Although the Company has attempted to identify important factors that could cause actual results, actions, events, conditions, performance or achievements to differ materially from those contained in forward-looking statements, there may be other factors that cause results, actions, events, conditions, performance or achievements to differ from those anticipated, estimated or intended.

Forward-looking statements are not a guarantee of future performance. There can be no assurance that forward-looking statements will prove to be accurate, as actual results and future events could differ materially from those anticipated in such statements. Forward-looking statements involve statements about the future and are inherently uncertain, and the Company’s actual results, achievements or other future events or conditions may differ materially from those reflected in the forward-looking statements due to a variety of risks, uncertainties and other factors, including, without limitation, those referred to herein and in the AIF under the heading “Risk Factors”.

The Company’s forward-looking statements are based on the assumptions, beliefs, expectations and opinions of management on the date the statements are made, many of which may be difficult to predict and beyond the Company’s control. In connection with the forward-looking statements contained in this MD&A and in the AIF, the Company has made certain assumptions about, among other things: favourable equity and debt capital markets; the ability to raise any necessary additional capital on reasonable terms to advance the production, development and exploration of the Company’s properties and assets; future prices of copper, gold and other metal prices; the timing and results of exploration and drilling programs; the accuracy of any mineral reserve and mineral resource estimates; the geology of the Caraíba Operations, the Xavantina Operations and the Tucumã Operation being as described in the respective technical report for each property; production costs; the accuracy of budgeted exploration, development and construction costs and expenditures; the price of other commodities such as fuel; future currency exchange rates, interest rates and tariff rates; operating conditions being favourable such that the Company is able to operate in a safe, efficient and effective manner; work force continuing to remain healthy in the face of prevailing epidemics, pandemics or other health risks, political and regulatory stability; the receipt of governmental, regulatory and third party approvals, licenses and permits on favourable terms; obtaining required renewals for existing approvals, licenses and permits on favourable terms; requirements under applicable laws; sustained labour stability; stability in financial and capital goods markets; availability of equipment; positive relations with local groups and the Company’s ability to meet its obligations under its agreements with such groups; and satisfying the terms and conditions of the Company’s current loan arrangements. Although the Company believes that the assumptions inherent in forward-looking statements are reasonable as of the date of this MD&A, these assumptions are subject to significant business, social, economic, political, regulatory, competitive and other risks and

Ero Copper Corp. September 30, 2025 MD&A | Page 39

uncertainties, contingencies and other factors that could cause actual actions, events, conditions, results, performance or achievements to be materially different from those projected in the forward-looking statements. The Company cautions that the foregoing list of assumptions is not exhaustive. Other events or circumstances could cause actual results to differ materially from those estimated or projected and expressed in, or implied by, the forward-looking statements contained in this MD&A.

Forward-looking statements contained herein are made as of the date of this MD&A and the Company disclaims any obligation to update or revise any forward-looking statement, whether as a result of new information, future events or results or otherwise, except as and to the extent required by applicable securities laws.

Cautionary Notes Regarding Mineral Resource and Reserve Estimates

Unless otherwise indicated, all reserve and resource estimates included in this MD&A and the documents incorporated by reference herein have been prepared in accordance with Canadian NI 43-101 and the Canadian Institute of Mining, Metallurgy and Petroleum (the “CIM”) — CIM Definition Standards on Mineral Resources and Mineral Reserves, adopted by the CIM Council, as amended (the “CIM Standards”). NI 43-101 is a rule developed by the Canadian Securities Administrators that establishes standards for all public disclosure an issuer makes of scientific and technical information concerning mineral projects. Canadian standards, including NI 43-101, differ significantly from the requirements of the United States Securities and Exchange Commission (the “SEC”), and reserve and resource information included herein may not be comparable to similar information disclosed by U.S. companies.

ADDITIONAL INFORMATION

Additional information about Ero and its business activities, including the AIF, is available under the Company’s profile at www.sedarplus.ca and www.sec.gov.

Ero Copper Corp. September 30, 2025 MD&A | Page 40

Document

CONDENSED CONSOLIDATED INTERIM

FINANCIAL STATEMENTS

FOR THE THREE AND NINE MONTHS ENDED

SEPTEMBER 30, 2025 AND 2024

Ero Copper Corp.
Table of Contents
CONSOLIDATED FINANCIAL STATEMENTS
---	---
Condensed Consolidated Statements of Financial Position	1
Condensed Consolidated Statements of Operations and Comprehensive Income (Loss)	2
Condensed Consolidated Statements of Cash Flow	3
Condensed Consolidated Statements of Changes in Shareholders' Equity	4
NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
General
Note 1. Nature of Operations	5
Note 2. Basis of Preparation	5
Note 3. Segment Disclosure	6
Statements of Financial Position
Note 4. Inventories	10
Note 5. Other Current Assets	10
Note 6. Mineral Properties, Plant and Equipment	11
Note 7. Exploration and Evaluation Assets	12
Note 8. Deposits and Other Non-current Assets	12
Note 9. Accounts Payable and Accrued Liabilities	12
Note 10. Loans and Borrowings	13
Note 11. Deferred Revenue	15
Note 12. Other Non-current Liabilities	17
Note 13. Share Capital	17
Statements of Earnings
Note 14. Revenue	21
Note 15. Cost of Sales	22
Note 16. General and Administrative Expenses	22
Note 17. Finance Expense	23
Note 18. Foreign Exchange Gain (Loss)	23
Other Items
Note 19. Financial Instruments	23
Note 20. Supplemental Cash Flow Information	27
Ero Copper Corp.
---
Condensed Consolidated Statements of Financial Position
(Unaudited, Amounts in thousands of US Dollars)
	Notes	September 30, 2025		December 31, 2024
---	---	---	---	---	---
ASSETS
Current
Cash and cash equivalents		$	66,257	$	50,402
Trade receivables		11,132		18,399
Inventories	4	91,626		42,094
Income tax receivable		—		2,284
Other current assets	5	38,398		28,611
		207,413		141,790
Non-Current
Mineral properties, plant and equipment	6	1,605,684		1,258,494
Exploration and evaluation assets	7	29,025		11,352
Deferred income tax assets		1,823		16,659
Deposits and other non-current assets	8	32,376		29,733
		1,668,908		1,316,238
Total Assets		$	1,876,321	$	1,458,028
LIABILITIES
Current
Accounts payable and accrued liabilities	9	$	164,140	$	101,886
Current portion of loans and borrowings	10	50,590		45,893
Current portion of deferred revenue	11	14,179		31,712
Income taxes payable		2,507		3,330
Current portion of derivatives	19	3,903		17,980
Current portion of lease liabilities		17,260		10,905
		252,579		211,706
Non-Current
Loans and borrowings	10	561,146		556,296
Deferred revenue	11	94,913		48,231
Provision for rehabilitation and closure costs		26,201		21,891
Deferred income tax liabilities		5,056		—
Lease liabilities		9,385		6,980
Other non-current liabilities	12	35,542		21,850
		732,243		655,248
Total Liabilities		984,822		866,954
SHAREHOLDERS’ EQUITY
Share capital	13	290,961		286,548
Equity reserves		(73,630)		(180,472)
Retained earnings		667,808		481,055
Equity attributable to owners of the Company		885,139		587,131
Non-controlling interests		6,360		3,943
		891,499		591,074
Total Liabilities and Equity		$	1,876,321	$	1,458,028
Commitments (Notes 7 and 11)
---	---	---	---	---
APPROVED ON BEHALF OF THE BOARD:
	"Makko DeFilippo"	, President, CEO and Director	"Jill Angevine"	, Director

The accompanying notes are an integral part of these condensed consolidated interim financial statements Page 1

Ero Copper Corp.
Condensed Consolidated Statements of Operations and Comprehensive Income (Loss)
(Unaudited, Amounts in thousands of US Dollars, except share and per share amounts)				Three months ended September 30,				Nine months ended September 30,
---	---	---	---	---	---	---	---	---	---
	Notes	2025		2024		2025		2024
Revenue	14	$	177,092	$	124,837	$	465,690	$	347,720
Cost of sales	15	(119,695)		(71,128)		(285,485)		(219,542)
Gross profit		57,397		53,709		180,205		128,178
Expenses
General and administrative	16	(12,580)		(12,628)		(35,515)		(35,952)
Share-based compensation	13 (e)	(6,742)		(4,859)		(15,671)		(17,479)
Write-down of exploration and evaluation asset	7	—		(467)		—		(11,212)
Operating Income		38,075		35,755		129,019		63,535
Finance income		1,208		781		3,176		3,610
Finance expense	17	(11,331)		(4,039)		(22,030)		(13,238)
Foreign exchange gain (loss)	18	22,055		17,246		119,095		(72,204)
Other expenses		(720)		(45)		(495)		(2,354)
Income (loss) before income taxes		49,287		49,698		228,765		(20,651)
Current income tax expense		(8,086)		(4,873)		(21,109)		(11,079)
Deferred income tax (expense) recovery		(4,688)		(3,458)		(19,488)		12,868
Income tax (expense) recovery		(12,774)		(8,331)		(40,597)		1,789
Net income (loss) for the period		$	36,513	$	41,367	$	188,168	$	(18,862)
Other comprehensive gain (loss)
Foreign currency translation gain (loss)		22,429		13,757		106,051		(85,881)
Comprehensive income (loss)		$	58,942	$	55,124	$	294,219	$	(104,743)
Net income (loss) attributable to:
Owners of the Company		35,978		40,857		186,753		(19,531)
Non-controlling interests		535		510		1,415		669
		$	36,513	$	41,367	$	188,168	$	(18,862)
Comprehensive income (loss) attributable to:
Owners of the Company		58,205		54,487		291,802		(104,691)
Non-controlling interests		737		637		2,417		(52)
		$	58,942	$	55,124	$	294,219	$	(104,743)
Net income (loss) per share attributable to owners of the Company
Basic	13 (f)	$	0.35	$	0.40	$	1.80	$	(0.19)
Diluted	13 (f)	$	0.35	$	0.39	$	1.80	$	(0.19)
Weighted average number of common shares outstanding
Basic	13 (f)	103,621,631		103,239,881		103,589,664		103,026,138
Diluted	13 (f)	104,044,755		103,973,827		103,941,295		103,026,138

The accompanying notes are an integral part of these condensed consolidated interim financial statements Page 2

Ero Copper Corp.
Condensed Consolidated Statements of Cash Flow
(Unaudited, Amounts in thousands of US Dollars)
		Three months ended September 30,				Nine months ended September 30,
---	---	---	---	---	---	---	---	---	---
	Notes	2025		2024		2025		2024
Cash Flows from Operating Activities
Net income (loss) for the period		$	36,513	$	41,367	$	188,168	$	(18,862)
Adjustments for:
Amortization and depreciation		31,369		21,555		75,204		67,145
Income tax expense (recovery)		12,774		8,331		40,597		(1,789)
Amortization of deferred revenue	14	(2,967)		(7,055)		(8,620)		(18,063)
Share-based compensation	13 (e)	6,742		4,859		15,671		17,479
Finance income		(1,208)		(781)		(3,176)		(3,610)
Finance expenses	17	11,331		4,039		22,030		13,238
Foreign exchange (gain) loss		(16,156)		(17,170)		(112,264)		67,655
Write-down of exploration and evaluation asset		—		467		—		11,212
Other		2,161		844		4,598		3,136
Changes in non-cash working capital items	20	30,828		2,234		(1,447)		(42,139)
		111,387		58,690		220,761		95,402
Advance from Xavantina Gold Stream	11	—		3,249		50,000		4,354
Derivative contract settlements		1,451		(4,575)		(548)		(5,285)
Provision settlements		(1,376)		(2,460)		(2,576)		(4,218)
Income taxes paid		(1,149)		(2,229)		(1,628)		(5,631)
		110,313		52,675		266,009		84,622
Cash Flows used in Investing Activities
Additions to mineral properties, plant and equipment		(69,880)		(74,480)		(192,400)		(256,013)
Additions to exploration and evaluation assets		(6,748)		(3,351)		(15,046)		(4,845)
Proceeds from short-term investments and interest received		790		467		2,072		1,865
		(75,838)		(77,364)		(205,374)		(258,993)
Cash Flows used in Financing Activities
Lease liability payments		(4,530)		(3,400)		(13,051)		(10,050)
New loans and borrowings, net of transaction costs	10	2,138		20,722		57,404		147,266
Loans and borrowings repaid	10	(11,676)		(3,939)		(43,300)		(30,216)
Interest paid on loans and borrowings	10	(17,368)		(14,642)		(38,727)		(29,376)
Other finance expenses paid		(1,758)		(1,026)		(6,588)		(3,129)
Proceeds from exercise of stock options		2,389		1,242		2,873		8,325
		(30,805)		(1,043)		(41,389)		82,820
Effect of exchange rate changes on cash and cash equivalents		(5,716)		1,188		(3,391)		42
Net (decrease) increase in cash and cash equivalents		(2,046)		(24,544)		15,855		(91,509)
Cash and cash equivalents - beginning of period		68,303		44,773		50,402		111,738
Cash and cash equivalents - end of period		$	66,257	$	20,229	$	66,257	$	20,229

Supplemental cash flow information (note 20)

The accompanying notes are an integral part of these condensed consolidated interim financial statements Page 3

Ero Copper Corp.
Condensed Consolidated Statements of Changes in Shareholders' Equity
(Unaudited, Amounts in thousands of US Dollars, except share and per share amounts)
		Share Capital			Equity Reserves
---	---	---	---	---	---	---	---	---	---	---	---	---	---	---	---	---
	Notes	Number of<br>shares	Amount		Contributed <br>Surplus		Foreign<br>Exchange		Retained<br>Earnings		Total		Non-controlling<br>interest		Total equity
Balance, December 31, 2023		102,747,558	$	271,336	$	8,497	$	(25,113)	$	549,530	$	804,250	$	5,081	$	809,331
Income (loss) for the period		—	—		—		—		(19,531)		(19,531)		669		(18,862)
Other comprehensive loss for the period		—	—		—		(85,160)		—		(85,160)		(721)		(85,881)
Total comprehensive loss for the period		—	—		—		(85,160)		(19,531)		(104,691)		(52)		(104,743)
Shares issued for:
Exercise of options		549,491	11,574		(3,249)		—		—		8,325		—		8,325
Share-based compensation	13 (e)	—	—		4,012		—		—		4,012		—		4,012
Dividends to non-controlling interest		—	—		—		—		—		—		(156)		(156)
Balance, September 30, 2024		103,297,049	$	282,910	$	9,260	$	(110,273)	$	529,999	$	711,896	$	4,873	$	716,769
Balance, December 31, 2024		103,555,211	$	286,548	$	8,181	$	(188,653)	$	481,055	$	587,131	$	3,943	$	591,074
Income for the period		—	—		—		—		186,753		186,753		1,415		188,168
Other comprehensive income for the period		—	—		—		105,049		—		105,049		1,002		106,051
Total comprehensive income for the period		—	—		—		105,049		186,753		291,802		2,417		294,219
Shares issued for:
Exercise of options		225,508	4,190		(1,317)		—		—		2,873		—		2,873
Settlement of restricted share units		7,113	145		(255)		—		—		(110)		—		(110)
Settlement of performance share units		5,812	78		—		—		—		78		—		78
Share-based compensation	13 (e)	—	—		3,365		—		—		3,365		—		3,365
Balance, September 30, 2025		103,793,644	$	290,961	$	9,974	$	(83,604)	$	667,808	$	885,139	$	6,360	$	891,499

The accompanying notes are an integral part of these condensed consolidated interim financial statements Page 4

Ero Copper Corp.
Condensed Consolidated Statements of Changes in Shareholders' Equity
(Unaudited, Amounts in thousands of US Dollars, except share and per share amounts)

1. Nature of Operations

Ero Copper Corp. (“Ero" or the "Company") was incorporated on May 16, 2016 under the Business Corporations Act (British Columbia) and maintains its head office at Suite 1050, 625 Howe Street, Vancouver, British Columbia, Canada, V6C 2T6. The Company’s shares are publicly traded on the Toronto Stock Exchange and the New York Stock Exchange under the symbol “ERO”.

The Company’s primary asset is its 99.6% ownership interest in Mineração Caraíba S.A. (“MCSA”), held indirectly through its wholly-owned subsidiary, Ero Brasil Participaçoes Ltda. The Company also currently owns a 97.6% ownership interest in NX Gold S.A. (“NX Gold”) indirectly through its wholly-owned subsidiary, Ero Gold Corp. (“Ero Gold”).

MCSA is a Brazilian copper company which holds a 100% interest in the Caraíba Operations, located in the State of Bahia, and the Tucumã Operation, located in the southeastern part of the State of Pará. MCSA’s predominant activity is the production and sale of copper concentrates, with gold and silver produced and sold as by-products.

NX Gold is a Brazilian gold mining company which holds a 100% interest in the Xavantina Operations and is focused on the production and sale of gold as its main product and silver as its by-product. The Xavantina Operations are located approximately 18 kilometers west of the town of Nova Xavantina, in southeastern State of Mato Grosso, Brazil.

2. Basis of Preparation

(a) Statement of Compliance

These condensed consolidated interim financial statements have been prepared in accordance with International Accounting Standards (“IAS”) 34, Interim Financial Reporting and follow the same accounting policies and methods of application as the Company’s most recent annual consolidated financial statements for the year ended December 31, 2024.

These condensed consolidated interim financial statements do not include all of the information required for full consolidated annual financial statements and should be read in conjunction with the consolidated financial statements of the Company as at and for the year ended December 31, 2024, prepared in accordance with International Financial Reporting Standards (“IFRS”) as issued by the International Accounting Standards Board (“IASB”).

These condensed consolidated interim financial statements were authorized for issue by the Board of Directors of the Company (the “Board”) on November 4, 2025.

(b) Use of Estimates and Judgments

In preparing these condensed consolidated interim financial statements, management has made judgments, estimates and assumptions that affect the application of the Company’s accounting policies and the reported amounts of assets, liabilities, income and expense. Actual results may differ. Significant judgments made by management in applying the Company’s accounting policies and key sources of estimation uncertainty were the same as those applied in the most recent annual audited consolidated financial statements for the year ended December 31, 2024.

Notes to Financial Statements | Page 5

Ero Copper Corp.
Notes to Condensed Consolidated Interim Financial Statements
(Unaudited, Tabular amounts in thousands of US Dollars, except share and per share amounts)

3. Segment Disclosure

Operating segments are determined by the way information is reported and used by the Company's Chief Operating Decision Maker ("CODM") to review operating performance. The Company monitors the operating results of its operating segments independently for the purpose of making decisions about resource allocation and performance assessment.

For the three and nine months ended September 30, 2025, the Company’s reporting segments include its three operating mines in Brazil, the Caraíba Operations, the Tucumã Operation, and the Xavantina Operations, and its corporate head office in Canada. Significant information relating to the Company's reportable segments is summarized in the tables below:

Three months ended September 30, 2025	Caraíba <br>(Brazil)		Tucumã<br><br>(Brazil)		Xavantina<br>(Brazil)		Corporate and Other		Consolidated
Revenue	$	90,598	$	59,122	$	27,372	$	—	$	177,092
Cost of production	(50,261)		(18,308)		(10,032)		—		(78,601)
Depreciation and depletion	(20,233)		(5,663)		(5,061)		—		(30,957)
Sales expense	(2,858)		(5,869)		(340)		—		(9,067)
Restructuring expense	(1,070)		—		—		—		(1,070)
Cost of sales	(74,422)		(29,840)		(15,433)		—		(119,695)
Gross profit	16,176		29,282		11,939		—		57,397
Expenses
General and administrative	(5,268)		(2,615)		(1,806)		(2,891)		(12,580)
Share-based compensation	—		—		—		(6,742)		(6,742)
Operating income (loss)	$	10,908	$	26,667	$	10,133	$	(9,633)	$	38,075
Capital expenditures(1)	48,355		6,124		8,572		6,692		69,743

(1) Capital expenditures include additions to mineral properties, plant and equipment and additions to exploration and evaluation asset, net of non-cash additions such as change in estimates to mine closure costs, capitalized depreciation expense, capitalized borrowing costs, and additions of right-of-use assets.

Notes to Financial Statements | Page 6

Ero Copper Corp.
Notes to Condensed Consolidated Interim Financial Statements
(Unaudited, Tabular amounts in thousands of US Dollars, except share and per share amounts)
Three months ended September 30, 2024	Caraíba <br>(Brazil)		Tucumã (Brazil)		Xavantina<br>(Brazil)		Corporate and Other		Consolidated
---	---	---	---	---	---	---	---	---	---	---
Revenue	$	87,305	$	3,099	$	34,433	$	—	$	124,837
Cost of production	(40,149)		(737)		(6,220)		—		(47,106)
Depreciation and depletion	(16,610)		(49)		(4,512)		—		(21,171)
Sales expense	(2,234)		(152)		(465)		—		(2,851)
Cost of sales	(58,993)		(938)		(11,197)		—		(71,128)
Gross profit	28,312		2,161		23,236		—		53,709
Expenses
General and administrative	(6,357)		(915)		(1,637)		(3,719)		(12,628)
Share-based compensation	—		—		—		(4,859)		(4,859)
Write-down of exploration and evaluation assets	(467)		—		—		—		(467)
Operating income (loss)	$	21,488	$	1,246	$	21,599	$	(8,578)	$	35,755
Capital expenditures(1)	37,204		23,517		6,119		2,984		69,824

Notes to Financial Statements | Page 7

Ero Copper Corp.
Notes to Condensed Consolidated Interim Financial Statements
(Unaudited, Tabular amounts in thousands of US Dollars, except share and per share amounts)
Nine months ended September 30, 2025	Caraíba <br>(Brazil)		Tucumã<br><br>(Brazil)		Xavantina<br>(Brazil)		Corporate and Other		Consolidated
---	---	---	---	---	---	---	---	---	---	---
Revenue	$	242,272	$	155,010	$	68,408	$	—	$	465,690
Cost of production	(132,870)		(35,508)		(25,018)		—		(193,396)
Depreciation and depletion	(54,222)		(5,738)		(14,129)		—		(74,089)
Sales expense	(5,985)		(10,099)		(846)		—		(16,930)
Restructuring expense	(1,070)		—		—		—		(1,070)
Cost of sales	(194,147)		(51,345)		(39,993)		—		(285,485)
Gross profit	48,125		103,665		28,415		—		180,205
Expenses
General and administrative	(14,689)		(7,149)		(4,923)		(8,754)		(35,515)
Share-based compensation	—		—		—		(15,671)		(15,671)
Operating income (loss)	$	33,436	$	96,516	$	23,492	$	(24,425)	$	129,019
Capital expenditures(1)	130,749		39,675		19,152		14,852		204,428
Assets
Current	$	95,066	$	54,306	$	44,594	$	13,447	207,413
Non-current	1,018,755		504,066		116,543		29,544		1,668,908
Total Assets	$	1,113,821	$	558,372	$	161,137	$	42,991	$	1,876,321
Total Liabilities	$	175,139	$	37,494	$	163,846	$	608,343	$	984,822

During the nine months ended September 30, 2025, the Company had six significant customers (September 30, 2024 - six), including four copper customers (September 30, 2024 - four) and two gold customers (September 30, 2024 - two).

Notes to Financial Statements | Page 8

Ero Copper Corp.
Notes to Condensed Consolidated Interim Financial Statements
(Unaudited, Tabular amounts in thousands of US Dollars, except share and per share amounts)
Nine months ended September 30, 2024	Caraíba <br>(Brazil)		Tucumã (Brazil)		Xavantina<br>(Brazil)		Corporate and Other		Consolidated
---	---	---	---	---	---	---	---	---	---	---
Revenue	$	240,104	$	3,099	$	104,517	$	—	$	347,720
Cost of production	(124,321)		(737)		(21,055)		—		(146,113)
Depreciation and depletion	(50,007)		(49)		(15,816)		—		(65,872)
Sales expense	(5,906)		(152)		(1,499)		—		(7,557)
Cost of sales	(180,234)		(938)		(38,370)		—		(219,542)
Gross profit	59,870		2,161		66,147		—		128,178
Expenses
General and administrative	(19,647)		(915)		(4,800)		(10,590)		(35,952)
Share-based compensation	—		—		—		(17,479)		(17,479)
Write-down of exploration and evaluation asset	(467)		—		—		(10,745)		(11,212)
Operating income (loss)	$	39,756	$	1,246	$	61,347	$	(38,814)	$	63,535
Capital expenditures(1)	113,638		113,286		16,659		4,767		248,350
Assets
Current	$	66,955	$	22,568	$	21,808	$	15,477	126,808
Non-current	865,291		421,307		89,236		9,880		1,385,714
Total Assets	$	932,246	$	443,875	$	111,044	$	25,357	$	1,512,522
Total Liabilities	$	167,099	$	29,226	$	85,658	$	513,770	795,753

Notes to Financial Statements | Page 9

Ero Copper Corp.
Notes to Condensed Consolidated Interim Financial Statements
(Unaudited, Tabular amounts in thousands of US Dollars, except share and per share amounts)

4. Inventories

	September 30, 2025		December 31, 2024
Supplies and consumables	$	47,216	$	28,980
Stockpiles	22,476		5,024
Work in progress	6,373		3,049
Finished goods	15,561		5,041
	$	91,626	$	42,094

5. Other Current Assets

	September 30, 2025		December 31, 2024
Advances to suppliers	$	3,830	$	3,157
Prepaid expenses and other	6,989		5,879
Derivatives (Note 19)	8,623		—
Note receivable (Note 19)	5,630		4,678
Value added taxes recoverable	13,326		14,897
	$	38,398	$	28,611

Notes to Financial Statements | Page 10

Ero Copper Corp.
Notes to Condensed Consolidated Interim Financial Statements
(Unaudited, Tabular amounts in thousands of US Dollars, except share and per share amounts)

6. Mineral Properties, Plant and Equipment

	Buildings		Mining Equipment		Mineral<br><br>Properties(1)		Projects in<br><br>Progress(2)		Equipment & Other Assets		Deposit on Projects		Mine Closure Costs		Right-of-Use Assets		Total
Cost:
Balance, December 31, 2024	36,593		294,944		643,758		501,057		26,972		12,700		21,336		49,995		1,587,355
Additions	405		19,155		72,943		83,251		3,749		10,187		—		20,093		209,783
Capitalized borrowing costs	—		—		—		26,998		—		—		—		—		26,998
Disposals	—		(43)		—		—		(7)		—		—		(3,658)		(3,708)
Transfers	48,963		131,570		208,958		(369,511)		143		(20,123)		—		—		—
Foreign exchange	9,102		57,851		120,331		52,408		4,390		1,437		3,499		8,996		258,014
Balance, September 30, 2025	$	95,063	$	503,477	$	1,045,990	$	294,203	$	35,247	$	4,201	$	24,835	$	75,426	$	2,078,442
Accumulated depreciation:
Balance, December 31, 2024	(7,219)		(73,675)		(199,911)		—		(9,210)		—		(5,574)		(33,272)		(328,861)
Depreciation expense	(3,115)		(26,042)		(43,288)		—		(1,626)		—		(813)		(13,341)		(88,225)
Disposals	—		33		—		—		—		—		—		2,281		2,314
Foreign exchange	(1,336)		(13,536)		(34,698)		—		(1,435)		—		(961)		(6,020)		(57,986)
Balance, September 30, 2025	$	(11,670)	$	(113,220)	$	(277,897)	$	—	$	(12,271)	$	—	$	(7,348)	$	(50,352)	$	(472,758)
Net book value, December 31, 2024	$	29,374	$	221,269	$	443,847	$	501,057	$	17,762	$	12,700	$	15,762	$	16,723	$	1,258,494
Net book value, September 30, 2025	$	83,393	$	390,257	$	768,093	$	294,203	$	22,976	$	4,201	$	17,487	$	25,074	$	1,605,684

(1) Mineral properties include $66.1 million (2024 - $57.9 million) of costs on expansion of near-mine resource potential which are not currently being depreciated.

On July 1, 2025, the Company announced that Tucumã Operation achieved commercial production which is the point at which the mine is capable of operating in the manner intended by the Company's management. Upon commercial production, $388.1 million of Projects in Progress was allocated to specific mineral properties, plant and equipment categories.

Notes to Financial Statements | Page 11

Ero Copper Corp.
Notes to Condensed Consolidated Interim Financial Statements
(Unaudited, Tabular amounts in thousands of US Dollars, except share and per share amounts)

7. Exploration and Evaluation Assets

As at September 30, 2025, the Company had $29.0 million (2024 - $11.4 million) in exploration and evaluation assets, which include several property option agreements.

In July 2024, the Company signed a definitive earn-in agreement (the "Agreement") with Salobo Metais S.A, a subsidiary of Vale Base Metals ("VBM"), for the Furnas copper project ("Furnas Project") located in the Carajás Mineral Province in Pará State, Brazil. The Agreement contemplates the Company earning a 60% interest in the Project upon completion of three phases of work:

•Phase 1: Ero to conduct a minimum of 28,000 meters of exploration drilling and produce a scoping study within 18 months of signing the Agreement (completed)

•Phase 2: Ero to conduct an additional minimum of 17,000 meters of exploration drilling and produce a pre-feasibility study within 18 months of completing Phase 1

•Phase 3: Ero to conduct an additional minimum of 45,000 meters of exploration drilling, unless otherwise mutually agreed, and produce a definitive feasibility study ("DFS") within 24 months of completing Phase 2

Following the completion of a DFS, subject to customary technical review periods, and with Ero positive investment approval, the parties will enter into a joint venture agreement whereby VBM will transfer 60% of the equity interest in the Furnas Project to Ero, and Ero will grant VBM a "free carry" on certain capital expenditures related to development of the Furnas Project.

Prior to a positive Ero investment decision and the formation of a joint venture, VBM will retain 100% ownership of the Furnas Project with Ero solely responsible for funding the phased exploration and engineering work programs as well as ongoing payments to maintain the property in good standing.

As at September 30, 2025, exploration and evaluation assets include $19.7 million (2024 - $4.9 million) in expenditures associated with the Furnas Project.

In June 2024, the Company terminated the Fides option agreement, resulting in a write-down of $10.7 million in exploration and evaluation assets.

Deposits and Other Non-current Assets

	September 30, 2025		December 31, 2024
Value added taxes recoverable	$	20,326	$	18,336
Note receivable (Note 19)	7,858		7,331
Deposits and others	4,192		4,066
	$	32,376	$	29,733

Notes to Financial Statements | Page 12

Ero Copper Corp.
Notes to Condensed Consolidated Interim Financial Statements
(Unaudited, Tabular amounts in thousands of US Dollars, except share and per share amounts)

9. Accounts Payable and Accrued Liabilities

	September 30, 2025		December 31, 2024
Trade suppliers	$	91,267	$	58,067
Payroll and labour related liabilities	25,696		19,086
Value added tax, royalty and other tax payable	10,299		8,505
Cash-settled equity awards (Note 13(b) and (c))	13,751		8,460
Customer advance	15,011		—
Provision for rehabilitation and closure costs	7,188		6,766
Other accrued liabilities	928		1,002
	$	164,140	$	101,886

10. Loans and Borrowings

							Carrying value, <br>including accrued interest
Description	Currency	Security	Maturity<br>(Months)	Coupon rate	Principal to be repaid		September 30, <br>2025		December 31,<br>2024
Senior Notes	USD	Unsecured	52	6.50%	$	400,000	$	398,353	$	404,152
Senior credit facility	USD	Secured	39	SOFR plus<br><br>2.00% - 4.25%	155,000		154,474		134,212
Copper Prepayment Facility	USD	Secured	15	8.66%	45,635		48,335		46,530
Equipment finance loans	USD	Secured	3 - 45	5.00% - 8.35%	9,122		9,220		12,933
Equipment finance loans	EUR	Secured	5 - 9	5.25%	279		279		544
Equipment finance loans	BRL	Unsecured	1 - 8	nil% - 16.63%	180		209		2,597
Bank loan	BRL	Unsecured	14	CDI + 0.50%	861		866		1,221
Total					$	611,077	$	611,736	$	602,189
Current portion							$	50,590	$	45,893
Non-current portion							$	561,146	$	556,296

Notes to Financial Statements | Page 13

Ero Copper Corp.
Notes to Condensed Consolidated Interim Financial Statements
(Unaudited, Tabular amounts in thousands of US Dollars, except share and per share amounts)

The movements in loans and borrowings are comprised of the following:

	Nine months ended September 30, 2025										Year ended<br><br>December 31,<br><br>2024
	Senior Notes		Senior Credit Facility		Copper Prepayment Facility		Other		Consolidated		Consolidated
Balance, beginning of period	$	404,152	$	134,212	$	46,530	$	17,295	$	602,189	$	426,233
Proceeds from loans and borrowings			30,000		25,000		2,404		57,404		214,565
Principal payments	—		(10,000)		(23,810)		(9,490)		(43,300)		(39,950)
Interest payments	(26,000)		(8,902)		(3,022)		(803)		(38,727)		(32,166)
Interest costs, including interest capitalized	20,201		9,164		3,637		661		33,663		36,467
Deferred transaction costs	—		—		—		—		—		(2,143)
Foreign exchange	—		—		—		507		507		(817)
Balance, end of period	$	398,353	$	154,474	$	48,335	$	10,574	$	611,736	$	602,189

(a) Senior Notes

In February 2022, the Company issued $400 million aggregate principal amount of senior unsecured notes (the “Senior Notes”). The Company received net proceeds of $392.0 million after transaction costs of $8.0 million. The Senior Notes mature on February 15, 2030 and bear annual interest at 6.5%, payable semi-annually in February and August of each year.

MCSA has provided a guarantee of the Senior Notes on a senior unsecured basis. The Senior Notes are direct, senior obligations of the Company and MCSA, and are not secured by any mortgage, pledge or charge.

The Company has the option to redeem, in whole or in part, the Senior Notes at a price ranging from 103.25% to 100% of the principal amount together with accrued and unpaid interest, if any, to the date of redemption, with the rate decreasing based on the length of time the Senior Notes are outstanding.

Upon the occurrence of specific kinds of changes of control triggering events, each holder of the Senior Notes will have the right to cause the Company to repurchase some or all of its Senior Notes at 101% of their principal amount, plus accrued and unpaid interest to, but not including, the repurchase date.

The Senior Notes are recognized as financial liabilities, net of unamortized transaction costs, and measured at amortized cost using an effective interest rate of 6.7%.

(b) Senior Credit Facility

In January 2025, the Company amended its Senior Revolving Credit Facility ("Amended Senior Credit Facility") to increase its borrowing limit from $150.0 million to $200.0 million and to extend the maturity from December 2026 to December 2028. The interest rates on the Amended Senior Credit Facility were reduced to sliding scales of SOFR plus 2.00% to 4.25% depending on the Company’s consolidated total leverage ratio. The commitment fees for any undrawn portion of the Senior Credit Facility were reduced to between 0.45% to 0.96% based on a sliding scale. The Company determined that the amendments were a non-substantial

Notes to Financial Statements | Page 14

Ero Copper Corp.
Notes to Condensed Consolidated Interim Financial Statements
(Unaudited, Tabular amounts in thousands of US Dollars, except share and per share amounts)

modification. As at September 30, 2025, the Senior Credit Facility bears a weighted average interest rate of 7.24% on its drawn balance and a commitment fee of 0.68% on its undrawn balance.

The Senior Credit Facility is secured by the shares of MCSA, NX Gold and Ero Gold. The Company is required to comply with certain financial covenants, which are required to be tested at each quarter end. These covenants include (a) a total leverage ratio based on total indebtedness to rolling four quarters adjusted earnings before interest, taxes, depreciation and amortization ("Rolling EBITDA"); (b) a total leverage ratio based on senior indebtedness to Rolling EBITDA; and (c) an interest coverage ratio based on Rolling EBITDA. The Senior Credit Facility provides for negative covenants customary for this type of facilities and permits additional equipment debt and finance leases of up to $50.0 million. As at September 30, 2025, the Company is in compliance with these financial covenants.

In May 2024, the Company entered into a non-priced copper prepayment facility with a bank syndicate. Under this facility, the Company received net proceeds of $49.6 million, representing gross proceeds of $50.0 million less transaction costs of $0.4 million. The Company had the option to increase the size of the non-priced copper prepayment facility from $50.0 million to $75.0 million until March 31, 2025.

In exchange, the Company is obligated to repay the $50.0 million facility over 27 equal monthly installments, beginning in October 2024, through the delivery of a minimum of 272 tonnes of copper each month. The copper to be delivered by the Company will be in the form of LME Copper Warrants. Each monthly delivery's value will be determined based on prevailing market copper prices at the time of delivery. Should the value of any delivery exceed the amount of the monthly installment payment of $2.1 million, the excess value will be repaid to the Company.

As the contractual obligation of the facility will be settled in the form of financial assets, the facility is accounted for as a financial liability measured at amortized cost using the effective interest rate method. Transaction costs are included in the initial measurement of the liability and amortized over the term of the facility.

The facility is secured by the shares of MCSA, NX Gold and Ero Gold.

Deferred Revenue

In 2021, the Company entered into a precious metals purchase agreement (the “Original Xavantina Stream”) with RGLD Gold AG ("Royal Gold"), a wholly-owned subsidiary of Royal Gold, Inc., in relation to gold production from the Xavantina Operations. The Company received upfront cash consideration of $100.0 million for the purchase of 25% of an equivalent amount of gold to be produced from the Xavantina mine until 93,000 ounces of gold have been delivered and thereafter decreasing to 10% of gold produced over the remaining life of the mine. The contract will be settled by the Company delivering gold to Royal Gold. Royal Gold will make ongoing payments equal to 20% of the then prevailing spot gold price for each ounce of gold delivered until 49,000 ounces of gold have been delivered and 40% of the prevailing spot gold price for each ounce of gold delivered thereafter. Additional advances may be made by Royal Gold based on the Company achieving certain milestones as set out in the Original Xavantina Stream.

Notes to Financial Statements | Page 15

Ero Copper Corp.
Notes to Condensed Consolidated Interim Financial Statements
(Unaudited, Tabular amounts in thousands of US Dollars, except share and per share amounts)

On March 28, 2025, the Company extended the terms of the Original Xavantina Stream with Royal Gold to expand the area of influence from which production is subjected to the arrangement to include additional tenements acquired by the Company since the Original Xavantina Stream was completed, and extend the gold delivery threshold milestones from 93,000 ounces of gold to 160,000 ounces of gold, before decreasing to 10% of gold produced over the remaining life of the mine. In exchange, the Company received additional upfront cash consideration of $50.0 million. The contract modification was accounted for as if the original contract was terminated and a new contract created. The remaining consideration received under the Original Xavantina Stream and the additional consideration received as a result of the modification will be allocated to future remaining gold deliveries based on stand alone selling prices on the contract modification date.

The movements in Xavantina Gold Stream deferred revenue during the nine months ended September 30, 2025 are comprised of the following:

	September 30, 2025		December 31,<br>2024
Gold ounces delivered in the period(1)	5,249		15,917
Balance, beginning of period	$	62,989	$	75,549
Advances	50,000		3,249
Accretion expense	4,723		2,501
Amortization of deferred revenue	(8,620)		(18,310)
Balance, end of period	$	109,092	$	62,989
Current portion	$	14,179	$	14,758
Non-current portion	94,913		48,231

(1) During the nine months ended September 30, 2025, the Company delivered 5,249 ounces of gold (December 31, 2024 - 15,917 ounces) to Royal Gold for average consideration of $835 per ounce (December 31, 2024 - $473 per ounce). At September 30, 2025, a cumulative 50,426 ounces (December 31, 2024 - 45,177 ounces) of gold have been delivered under the Xavantina Gold Stream.

(2) Amortization of deferred revenue during the nine months ended September 30, 2025 was net of $0.5 million (December 31, 2024 - $3.0 million) related to change in estimate attributed to advances received and change in life-of-mine production estimates.

As part of the Xavantina Gold Stream, the Company pledged its equity interest in Ero Gold and NX Gold to Royal Gold as collateral and provided unsecured limited recourse guarantees from Ero and NX Gold.

As of December 31, 2024, current portion of deferred revenue included $17.0 million in customer advances related to copper concentrate sales.

Notes to Financial Statements | Page 16

Ero Copper Corp.
Notes to Condensed Consolidated Interim Financial Statements
(Unaudited, Tabular amounts in thousands of US Dollars, except share and per share amounts)

Other Non-current Liabilities

	September 30, 2025		December 31, 2024
Cash-settled equity awards (Note 13(b))	$	9,350	$	2,536
Withholding, value added tax, and other taxes payable	20,568		14,437
Provision	1,539		1,588
Other liabilities	4,085		3,289
	$	35,542	$	21,850

Share Capital

(a) Options

During the nine months ended September 30, 2025, the Company granted 13,038 options (nine months ended September 30, 2024 - 31,251 options) to employees of the Company at weighted average exercise price of $18.10 CAD per share (nine months ended September 30, 2024 - $24.79 CAD per share) with a term to expiry of five years. These stock options vest in three equal installments on each annual anniversary date from the date of grant. The total fair value of these options on the grant date was $0.1 million (nine months ended September 30, 2024 - $0.3 million), which is recognized over the vesting period.

A continuity of the issued and outstanding options is as follows:

	Nine Months Ended September 30,
	2025			2024
	Number of <br>Stock Options	Weighted Average Exercise Price (CAD)		Number of <br>Stock Options	Weighted Average Exercise Price (CAD)
Outstanding stock options, beginning of period	1,734,607	$	19.07	1,886,325	$	19.03
Issued	13,038	18.10		31,251	24.79
Exercised	(225,508)	18.50		(549,491)	20.57
Forfeited	(83,371)	19.92		(1,034)	18.69
Outstanding stock options, end of period	1,438,766	$	19.10	1,367,051	$	18.54

The weighted average share price on the date of exercise for options exercised during the nine months ended September 30, 2025 was CAD$24.06 (nine months ended September 30, 2024 - CAD$29.45).

Notes to Financial Statements | Page 17

Ero Copper Corp.
Notes to Condensed Consolidated Interim Financial Statements
(Unaudited, Tabular amounts in thousands of US Dollars, except share and per share amounts)

As at September 30, 2025, the following stock options were outstanding:

Weighted Average Exercise Prices	Number of <br>Stock Options	Vested and Exercisable Number of Stock Options	Weighted Average Remaining Life in Years
$10.01 to $20.00 CAD	976,028	594,585	2.26
$20.01 to $25.35 CAD	462,738	58,630	4.05
$19.10 CAD ($13.72 USD)	1,438,766	653,215	2.84

The fair value of options granted was determined using the Black-Scholes option pricing model. The weighted average inputs used in the measurement of fair values at grant date of the options are the following:

	Nine Months Ended September 30,
	2025			2024
Expected term (years)	3.5			3.0
Forfeiture rate	2		%	—		%
Volatility	51		%	52		%
Dividend yield	—		%	—		%
Risk-free interest rate	2.60		%	3.12		%
Weighted-average fair value per option	$	5.06		$	8.79

(b) Performance Share Unit Plan

The Company has a performance share unit ("PSU") plan pursuant to which the Compensation Committee may grant PSUs to Eligible Persons of the Company or its subsidiaries. Each PSU entitles the holder thereof to receive one common share, its equivalent cash value, or a combination of both, on the redemption date at the discretion of the Compensation Committee.

The continuity of PSUs issued and outstanding is as follows:

	Nine Months Ended September 30,
	2025	2024
Outstanding balance, beginning of period	1,014,505	967,921
Issued	10,734	23,306
Settled	(12,500)	(7,668)
Forfeited	(52,829)	(10,000)
Outstanding balance, end of period	959,910	973,559

These PSUs will vest three years from the date of grant by the Compensation Committee and the number of PSUs that will vest may range from 0% to 200% of the number granted, subject to the satisfaction of certain market and non-market performance conditions. Each vested PSU entitles the holder thereof to receive on or

Notes to Financial Statements | Page 18

Ero Copper Corp.
Notes to Condensed Consolidated Interim Financial Statements
(Unaudited, Tabular amounts in thousands of US Dollars, except share and per share amounts)

about the applicable date of vesting of such share unit (i) one common share; (ii) a cash amount equal to the fair market value of one common share as at the applicable date of vesting; or (iii) a combination of (i) and (ii), as determined by the Compensation Committee in its sole discretion. The Company has elected to settle its PSUs using a combination of cash and common shares in the past. As such, based on its history of past settlements, PSUs are classified as liabilities.

For PSUs with non-market performance conditions, the fair value of the share units granted was initially recognized at the fair value using the share price at the date of grant, and subsequently remeasured at fair value on each balance sheet date. For PSUs with market performance conditions, the fair value was determined using a Geometric Brownian Motion model. As at September 30, 2025, the fair value of the PSU liability was $16.5 million (December 31, 2024 - $6.6 million) of which $7.1 million (December 31, 2024 - $4.1 million) was recognized in accounts payable and accrued liabilities and the remainder in other non-current liabilities.

The Deferred Share Unit ("DSU") plan was established by the Board as a component of compensation for the Company's independent directors. Pursuant to the DSU Plan, DSUs may only be settled by way of cash payment. A participant is not entitled to payment in respect of the DSUs until his or her death, retirement or removal from the Board. The settlement amount of each DSU is based on the fair market value of a common share on the DSU redemption date multiplied by the number of DSUs being redeemed.

The continuity of DSUs issued and outstanding is as follows:

	Nine months ended September 30,
	2025	2024
Outstanding balance, beginning of period	325,111	307,312
Issued	13,904	12,826
Settled	(12,882)	—
Outstanding balance, end of period	326,133	320,138

At September 30, 2025, DSU liabilities had a fair value of $6.6 million (December 31, 2024 - $4.4 million) which has been recognized in accounts payable and accrued liabilities.

(d) Restricted Share Unit Plan

The Company has a restricted share unit ("RSU") plan pursuant to which the Compensation Committee may grant share units to Eligible Persons of the Company or its subsidiaries. The fair value of these restricted share units is determined on the date of grant using the market price of the Company’s shares. Each RSU entitles the holder thereof to receive one common share, its equivalent cash value, or a combination of both, on the redemption date at the discretion of the Compensation Committee. The RSUs are equity classified based on the history of past settlements.

Notes to Financial Statements | Page 19

Ero Copper Corp.
Notes to Condensed Consolidated Interim Financial Statements
(Unaudited, Tabular amounts in thousands of US Dollars, except share and per share amounts)

The continuity of RSUs issued and outstanding is as follows:

	Nine months ended September 30,
	2025	2024
Outstanding balance, beginning of period	328,180	340,570
Issued	5,366	11,653
Settled	(12,217)	—
Forfeited	(13,314)	—
Outstanding balance, end of period	308,015	352,223

(e) Share-based compensation

	Three months ended September 30,				Nine months ended September 30,
	2025		2024		2025		2024
Stock options	$	592	$	674	$	1,677	$	2,033
Performance share unit plan	4,324		3,262		10,047		11,106
Deferred share unit plan	1,247		284		2,298		2,361
Restricted share unit plan	579		639		1,649		1,979
Share-based compensation(1)	$	6,742	$	4,859	$	15,671	$	17,479

(1) For the three and nine months ended September 30, 2025, the Company recorded $1.2 million and $3.3 million (three and nine months ended September 30, 2024 - $1.3 million and $4.0 million) of share-based compensation in contributed surplus, and the remaining share-based compensation was recorded in liabilities.

Notes to Financial Statements | Page 20

Ero Copper Corp.
Notes to Condensed Consolidated Interim Financial Statements
(Unaudited, Tabular amounts in thousands of US Dollars, except share and per share amounts)

(f) Net Income (Loss) per Share

	Three months ended September 30,				Nine months ended September 30,
	2025		2024		2025		2024
Weighted average number of common shares outstanding	103,621,631		103,239,881		103,589,664		103,026,138
Dilutive effects of:
Stock options	115,109		381,723		43,616		—
Share units	308,015		352,223		308,015		—
Weighted average number of diluted common shares outstanding(1)	104,044,755		103,973,827		103,941,295		103,026,138
Net income (loss) attributable to owners of the Company	$	35,978	$	40,857	$	186,753	$	(19,531)
Basic net income (loss) per share	$	0.35	$	0.40	$	1.80	$	(0.19)
Diluted net income (loss) per share	$	0.35	$	0.39	$	1.80	$	(0.19)

(1) Weighted average number of diluted common shares outstanding for the three and nine months ended September 30, 2025 excluded 464,486 and 839,668 (three and nine months ended September 30, 2024 - 31,251 and 1,367,051) stock options and nil share units (three and nine months ended September 30, 2024 - nil and 352,223) that were anti-dilutive.

Revenue

	Three months ended September 30,				Nine months ended September 30,
	2025		2024		2025		2024
Copper
Export sales	144,204		87,001		$	394,812	$	240,015
Adjustments on provisional sales(1)	5,516		3,403		2,470		3,188
	149,720		90,404		397,282		243,203
Gold
Sales	24,405		27,378		59,788		86,454
Amortization of deferred revenue(2)	2,967		7,055		8,620		18,063
	$	27,372	$	34,433	$	68,408	$	104,517
	$	177,092	$	124,837	$	465,690	$	347,720

(1) Adjustments on provisional sales include both pricing and quantity adjustments. Provisionally priced sales to the Company's international customers are settled with a final sales price between zero to six months (September 30, 2024 - zero to one month) after shipment takes place and, therefore, are exposed to commodity price changes.

(2) During the three and nine months ended September 30, 2025, the Company delivered 2,000 and 5,249 ounces of gold, respectively (three and nine months ended September 30, 2024 - 4,190 and 12,581 ounces of gold), under a precious metals purchase agreement with Royal Gold (note 11) for average cash consideration of $1,188 and $835 per ounce (three and nine months ended September 30, 2024 - $489 and $456).

Notes to Financial Statements | Page 21

Ero Copper Corp.
Notes to Condensed Consolidated Interim Financial Statements
(Unaudited, Tabular amounts in thousands of US Dollars, except share and per share amounts)

Cost of Sales

	Three months ended September 30,				Nine months ended September 30,
	2025		2024		2025		2024
Materials	$	20,286	$	11,710	$	45,094	$	34,013
Salaries and benefits	23,548		15,670		62,477		47,135
Contracted services	25,114		13,805		48,661		31,730
Maintenance costs	13,639		7,969		36,430		23,511
Utilities	5,352		2,782		13,607		9,667
Other costs	1,043		308		1,931		776
Change in inventory (excluding depreciation and depletion)	(10,381)		(5,138)		(14,804)		(719)
Cost of production	78,601		47,106		193,396		146,113
Sales expense and others	9,067		2,851		16,930		7,557
Restructuring cost(1)	1,070		—		1,070		—
Depreciation and depletion	42,743		21,772		86,802		64,006
Change in inventory (depreciation and depletion)	(11,786)		(601)		(12,713)		1,866
	$	119,695	$	71,128	$	285,485	$	219,542

(1) Restructuring cost mainly consist of severance payments.

General and Administrative Expenses

	Three months ended September 30,				Nine months ended September 30,
	2025		2024		2025		2024
Accounting and legal	$	570	$	463	$	1,427	$	1,525
Amortization and depreciation	412		384		1,115		1,273
Office and administration	2,203		2,461		6,853		6,992
Salaries and consulting fees	7,488		6,797		20,698		19,844
Incentive payments	1,011		1,541		3,087		4,209
Other	896		982		2,335		2,109
	$	12,580	$	12,628	$	35,515	$	35,952

Notes to Financial Statements | Page 22

Ero Copper Corp.
Notes to Condensed Consolidated Interim Financial Statements
(Unaudited, Tabular amounts in thousands of US Dollars, except share and per share amounts)

17. Finance Expense

	Three months ended September 30,				Nine months ended September 30,
	2025		2024		2025		2024
Interest on loans and borrowings(1)	$	6,665	$	—	$	6,665	$	—
Accretion of deferred revenue	1,998		592		$	4,723	$	1,918
Accretion of provision for rehabilitation and closure costs	901		566		2,608		1,802
Interest on lease liabilities	722		463		1,916		1,360
Other finance expenses(1)	1,045		2,418		6,118		8,158
	$	11,331	$	4,039	$	22,030	$	13,238

(1) Other finance expenses during the three and nine months ended September 30, 2025 included nil and $1.4 million, respectively (three and nine months ended September 30, 2024 - $1.8 million and $6.3 million) of credit loss on certain accounts receivable (see Note 19).

(2) During the three and nine months ended September 30, 2025, the Company capitalized $4.6 million and $27.0 million, respectively (three and nine months ended September 30, 2024 -$9.6 million and $26.1 million) of borrowing costs to projects in progress.

18. Foreign Exchange Gain (Loss)

The following foreign exchange gains (losses) arise as a result of balances and transactions in the Company’s Brazilian subsidiaries that are denominated in currencies other than the Brazilian Reals (BRL$), which is their functional currency.

	Three months ended September 30,				Nine months ended September 30,
	2025		2024		2025		2024
Foreign exchange gain (loss) on USD denominated debt in Brazil	$	16,994	$	10,993	$	95,104	$	(56,710)
Realized foreign exchange gain (loss) on derivative contracts (note 19)	2,046		(3,428)		47		(2,300)
Unrealized foreign exchange gain (loss) on derivative contracts (note 19)	3,980		9,847		27,419		(15,565)
Foreign exchange (loss) gain on other financial assets and liabilities	(965)		(166)		(3,475)		2,371
	$	22,055	$	17,246	$	119,095	$	(72,204)

19. Financial Instruments

Fair value

Fair values of financial assets and liabilities are determined based on available market information and valuation methodologies appropriate to each situation.

As at September 30, 2025, derivatives were measured at fair value based on Level 2 inputs.

Notes to Financial Statements | Page 23

Ero Copper Corp.
Notes to Condensed Consolidated Interim Financial Statements
(Unaudited, Tabular amounts in thousands of US Dollars, except share and per share amounts)

The carrying values of cash and cash equivalents, accounts receivable, deposits, and accounts payable and accrued liabilities approximate their fair values due to their short terms to maturity or the discount rate used approximates to the contractual interest rate. At September 30, 2025, the carrying value of loans and borrowings, including accrued interest, was $611.7 million while the fair value is approximately $612.5 million. At September 30, 2025, the carrying value of notes receivable, including accrued interest, was $13.5 million which approximates its fair value.

Credit risk

	September 30, 2025		December 31, 2024
Cash and cash equivalents	$	66,257	$	50,402
Accounts receivable	11,132		18,399
Derivatives	9,578		—
Note receivable	13,488		12,009
Deposits and other assets	5,679		4,961
	$	106,134	$	85,771

The Company invests cash and cash equivalents with financial institutions that are financially sound based on their credit rating.

The Company’s exposure to credit risk associated with accounts receivable is influenced mainly by the individual characteristics of each customer.

Notes to Financial Statements | Page 24

Ero Copper Corp.
Notes to Condensed Consolidated Interim Financial Statements
(Unaudited, Tabular amounts in thousands of US Dollars, except share and per share amounts)

Liquidity risk

The table below shows the Company's maturity of non-derivative financial liabilities on September 30, 2025:

Non-derivative financial liabilities	Carrying <br>value		Contractual cash flows		Up to <br>12 months		1 - 2 <br>years		3 - 5 <br>years		More than <br>5 years
Loans and borrowings (including interest)	$	611,736	$	771,569	$	86,052	$	86,948	$	598,569	$	—
Accounts payable and accrued liabilities	141,941		142,457		142,457		—		—		—
Other non-current liabilities	13,435		25,579		—		24,486		707		386
Leases	26,645		29,479		19,745		8,703		1,011		19
Total	$	793,757	$	969,084	$	248,254	$	120,137	$	600,287	$	405

The Company also has a derivative financial asset for foreign exchange collar contracts whose notional amounts and maturity information are disclosed below under foreign exchange currency risk.

Market risk

Market risk is the risk of loss that may arise from changes in market factors such as interest rates, foreign exchange rates, and commodity prices. The purpose of market risk management is to manage and control exposures to market risks, within acceptable parameters, while optimizing return.

The Company may use derivatives, including options, forwards and swap contracts, to manage market risks.

The Company's outstanding derivative instruments as of September 30, 2025 are as follows:

Contract Description	Notional Amount	Denomination	Weighted average floor	Weighted average cap / forward price	Maturities
Foreign exchange collar (i)	$289.5 million	USD/BRL	5.59	6.59	October 2025 - December 2026
Gold collar (iii)	7,500 ounces	$ / oz	$2,200	$3,425	October 2025 - December 2025

Notes to Financial Statements | Page 25

Ero Copper Corp.
Notes to Condensed Consolidated Interim Financial Statements
(Unaudited, Tabular amounts in thousands of US Dollars, except share and per share amounts)

(i) Foreign exchange currency risk

The Company may use certain foreign exchange derivatives, including collars and forward contracts, to manage its foreign exchange risks. At September 30, 2025, the aggregate fair value of the Company's foreign exchange derivatives was a net asset of $9.6 million of which $8.6 million is recorded in other current assets and $1.0 million in other non-current assets (December 31, 2024 - liability of $17.9 million). The fair values of foreign exchange contracts were determined based on option pricing models, forward foreign exchange rates, and information provided by the counter party.

The change in fair value of foreign exchange derivatives was a gain of $4.0 million and $27.4 million for the three and nine months ended September 30, 2025, respectively (a gain of $9.8 million and a loss of $15.6 million for the three and nine months ended September 30, 2024, respectively), and have been recognized in foreign exchange gain (loss).

In addition, during the three and nine months ended September 30, 2025, the Company recognized a realized gain of $2.0 million and nil, respectively (realized loss of $3.4 million and $2.3 million for the three and nine months ended September 30, 2024 respectively), related to the settlement of foreign currency forward collar contracts.

(ii) Interest rate risk

(iii) Price risk

The Company may use derivatives, including forward contracts, collars and swap contracts, to manage commodity price risks.

At September 30, 2025, the Company had gold collar contracts on 2,500 ounces of gold per month from October 2025 to December 2025. These gold derivative contracts establish an average floor price of $2,200 per ounce of gold and an average cap price of $3,425 per ounce. As of September 30, 2025, the fair value of these contracts was a net liability of $3.9 million (December 31, 2024 - liability of $0.1 million). The fair value of gold

Notes to Financial Statements | Page 26

Ero Copper Corp.
Notes to Condensed Consolidated Interim Financial Statements
(Unaudited, Tabular amounts in thousands of US Dollars, except share and per share amounts)

collar contracts was determined based on option pricing models, forward gold price, and information provided by counter party.

During the three and nine months ended September 30, 2025, the Company recognized an unrealized loss of $1.6 million and $3.1 million (unrealized gain of $0.4 million and nil for the three and nine months ended September 30, 2024), respectively, in relation to its commodity derivatives in other income or loss.

At September 30, 2025, the Company had provisionally priced sales that are exposed to commodity price changes (note 14). Based on the Company’s net exposure at September 30, 2025, a 10% change in the price of copper would have changed pre-tax net income (loss) by $3.9 million.

Supplemental Cash Flow Information

	Three months ended September 30,				Nine months ended September 30,
Net change in non-cash working capital items:	2025		2024		2025		2024
Accounts receivable	$	1,597	$	(4,110)	$	7,446	$	(15,353)
Inventories	(14,508)		(8,261)		(28,538)		(7,536)
Other assets	(3,220)		(7,975)		(6,758)		(18,362)
Accounts payable and accrued liabilities	46,959		22,580		26,403		(888)
	$	30,828	$	2,234	$	(1,447)	$	(42,139)
Non-cash investing and financing activities:
Additions to property, plant and equipment by leases	6,137		5,808		$	20,093	$	13,642
Non-cash decrease in accounts payable in relation to capital expenditures	(6,885)		(9,712)		(3,018)		(2,670)
Change in mineral properties, plant and equipment from change in estimates for provision for rehabilitation and closure costs	—		3,609		—		3,609

Notes to Financial Statements | Page 27

Document

	TSX: ERO
NYSE: ERO

November 4, 2025

Ero Copper Reports Third Quarter 2025 Operating and Financial Results

(all amounts in US dollars, unless otherwise noted)

Vancouver, British Columbia – Ero Copper Corp. (TSX: ERO, NYSE: ERO) (“Ero” or the “Company”) is pleased to announce its operating and financial results for the three and nine months ended September 30, 2025. Management will host a conference call tomorrow, Wednesday, November 5, 2025, at 11:30 a.m. Eastern time to discuss the results. Dial-in details for the call can be found near the end of this press release.

HIGHLIGHTS

◦The Caraíba Operations produced 9,085 tonnes of copper in concentrate at an average C1 cash cost(*) of $2.32 per pound.

◦The Tucumã Operation produced 7,579 tonnes of copper in concentrate, representing a quarter-on-quarter increase of 19%, at an average C1 cash cost(*) of $1.62 per pound.

•Quarterly gold production totaled 9,073 ounces, an increase of 17% compared to the prior period, at an average C1 cash cost(*) and All-in Sustaining Cost ("AISC")(*) of $1,086 and $2,425 per ounce, respectively.

◦Net income attributable to the owners of the Company for the quarter was $36.0 million ($0.35 per share on a diluted basis).

◦Adjusted net income attributable to the owners of the Company(1) for the quarter was $27.9 million ($0.27 per share on a diluted basis).

◦Adjusted EBITDA(1) was $77.1 million.

1	Ero Copper Corp
	625 Howe Street	Suite 1050	Vancouver	BC	V6C 2T6	Canada
	TSX: ERO
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NYSE: ERO

•At Xavantina, the Company launched a value-creation initiative in 2024 aimed at capturing value from stockpiled gold concentrates produced in small but high-grade quantities since processing operations began in 2012. During Q3 2025, these efforts culminated in an initial sales agreement, with shipments commencing in October. The Company expects to sell between 10,000 to 15,000 tonnes at an approximate gold grade of 30 to 40 grams per tonne during Q4 2025, and to complete sampling, shipments, and sales of the remaining volume over the next 12 to 18 months, which is expected to significantly bolster gold sales from the Xavantina Operations.

◦Operating costs for excavating, drying, loading, transportation and seaborne freight are expected to be approximately $300 to $500 per ounce.

•The Company is reaffirming full-year production and capital expenditure guidance for all assets, as well as full-year cost guidance for Caraíba and Xavantina, while increasing cost guidance for the Tucumã Operation to reflect higher-than-expected maintenance and freight costs. The Company continues to expect Q4 2025 to be the strongest production quarter of the year across its operations.

•During Q3 2025, the Company received full assay results for the 28,000-meter Phase 1 drill program at the Furnas Copper-Gold Project ("Furnas" or the "Project"), completed in July. Results from the program continue to demonstrate high-grade continuity throughout the deposit and significantly extend the known limits of mineralization within the high-grade zones (greater than 1% CuEq(2)) to depth.

◦Step-out drilling during Phase 1 extended the known limits of mineralization to approximately 950 meters down-dip from surface, representing a significant increase relative to the Project's National Instrument 43-101 ("NI 43-101") compliant mineral resource estimate, which is based on an average historical depth of drilling of 300 meters (vertical), with a maximum localized down-dip depth from surface of 580 meters. Phase 1 assay results, will support a preliminary economic assessment on the Project, including an updated NI

2	Ero Copper Corp
	625 Howe Street	Suite 1050	Vancouver	BC	V6C 2T6	Canada
	TSX: ERO
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NYSE: ERO

43-101 mineral resource estimate, which the Company plans to publish in H1 2026.

◦Subsequent to quarter-end, the Company completed the 17,000-metre Phase 2 drill program at Furnas. The Phase 2 program was completed approximately three months ahead of schedule, and the Company has commenced the Phase 3 drill program with 8 drill rigs currently operating on site.

"We are pleased with the continued progress across our operations, where the effort and investment we’ve made in optimization initiatives are driving sequential copper and gold production growth in the second half of 2025," said Makko DeFilippo, President and Chief Executive Officer. "Highlights include the transition from manual to mechanized mining at Xavantina that provides us with the opportunity to enhance our health and safety efforts at the mine while also increasing our development and exploration opportunities, the continued ramp-up at Tucumã, and encouraging results from Phase 1 and early completion of the Phase 2 drill program at Furnas. While Q3 represented another record consolidated copper production quarter, we are excited for how all of our operations are aligned heading into Q4, which we expect to be our strongest operating quarter of the year."

"We also announced a maiden inferred resource of gold concentrates at Xavantina, an important milestone from an initiative launched late last year to capture value from high-grade gold concentrates produced in small quantities and stockpiled at site over the past decade. This maiden inferred mineral resource estimate, which we published earlier today, was based on drilling and sampling of only a portion of the gold concentrate volumes. With further sampling underway to quantify the tonnage and grades of the remaining concentrate volume, we are excited for the potential opportunity this gold concentrate material represents."

3	Ero Copper Corp
	625 Howe Street	Suite 1050	Vancouver	BC	V6C 2T6	Canada
	TSX: ERO
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NYSE: ERO

THIRD QUARTER REVIEW

The Caraíba Operations

•Quarterly copper production totaled 9,085 tonnes of copper in concentrate, with an average C1 cash cost(*) of $2.32 per pound.

•Plant throughput increased 26% compared to Q2 2025, reaching record volumes of nearly 1.0 million tonnes for the period, supported by higher mining rates across all three mines and a successful multi-quarter mill debottlenecking program that enabled increased processing rates.

•Higher tonnes mined and processed during the period were offset by lower planned grades at both Vermelhos and Pilar. Consequently, C1 cash costs(1) increased 12% quarter-on-quarter.

The Tucumã Operation

•The Tucumã Operation produced 7,579 tonnes of copper in concentrate at an average C1 cash cost(1) of $1.62 per pound during the quarter.

•The quarter-on-quarter increase in production of 19% was driven by higher plant throughput as processing performance continued to improve through the period, partially offset by lower planned grades. Mining operations continued to perform well with over 1.3 million tonnes of ore mined during the period.

The Xavantina Operations

•Quarterly gold production totaled 9,073 ounces of gold, at C1 cash cost(*) and AISC(*) of $1,086 and $2,425, respectively, per ounce.

•The 17% quarter-on-quarter increase in production reflects higher throughput and processed grades as the transition to mechanized mining advanced in several key production areas of Santo Antônio. This resulted in more than 50,000 tonnes of ore mined during the quarter, a mine production rate last achieved in Q2 2022.

(*) These are non-IFRS measures and do not have a standardized meaning prescribed by IFRS and might not be comparable to similar financial measures disclosed by other issuers. Please refer to the Company’s discussion of Non-IFRS measures in its Management’s Discussion and Analysis for the three and nine months ended September 30, 2025 and the Reconciliation of Non-IFRS Measures section at the end of this press release.

4	Ero Copper Corp
	625 Howe Street	Suite 1050	Vancouver	BC	V6C 2T6	Canada
	TSX: ERO
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NYSE: ERO

OPERATING HIGHLIGHTS

	2025 - Q3		2025 - Q2		2024 - Q3		2025 - YTD		2024 - YTD
Copper (Caraíba Operations)
Ore Mined (tonnes)	1,018,972		792,764		874,937		2,507,975		2,560,430
Ore Processed (tonnes)	996,661		791,946		900,289		2,481,508		2,711,352
Grade (% Cu)	1.01		1.27		1.20		1.14		1.10
Recovery (%)	90.4		91.1		91.9		90.6		90.2
Cu Production (tonnes)	9,085		9,162		9,920		25,604		26,878
Cu Production (000 lbs)	20,030		20,199		21,871		56,448		59,257
Cu Sold in Concentrate (tonnes)	9,080		9,387		9,970		25,416		28,137
Cu Sold in Concentrate (000 lbs)	20,017		20,697		21,980		56,031		62,031
Cu C1 cash cost(1)(2)	$	2.32	$	2.07	$	1.63	$	2.20	$	2.01
Copper (Tucumã Operation)
Ore Mined (tonnes)	1,333,748		798,811		867,315		2,460,850		867,315
Ore Processed (tonnes)	575,041		418,699		110,778		1,288,054		110,778
Grade (% Cu)	1.51		1.74		1.00		1.74		1.00
Recovery (%)	89.2		85.4		75.70		88.0		75.70
Cu Production (tonnes)	7,579		6,351		839		18,997		839
Cu Production (000 lbs)	16,707		14,002		1,850		41,880		1,850
Cu Sold in Concentrate (tonnes)	6,622		5,968		357		17,758		357
Cu Sold in Concentrate (000 lbs)	14,598		13,158		787		39,149		787
Cu C1 cash cost(1)(2)	$	1.62	$	—	$	—	$	1.62	$	—
Gold (Xavantina Operations)
Ore Mined (tonnes)	50,268		37,829		41,761		121,325		120,041
Ore Processed (tonnes)	47,865		37,829		41,761		118,922		120,041
Grade (g / tonne)	8.15		7.11		11.41		7.46		13.85
Recovery (%)	78.4		88.7		92.5		84.7		91.8
Au Production (oz)	9,073		7,743		13,485		23,454		48,274
Au Sold (oz)	8,439		8,276		14,615		22,549		49,089
Au C1 cash cost(1)	$	1,086	$	1,115	$	539	$	1,100	$	447
Au AISC(1)	$	2,425	$	2,234	$	1,034	$	2,307	$	879

(1) EBITDA, adjusted EBITDA, adjusted net income (loss) attributable to owners of the Company, adjusted net income (loss) per share attributable to owners of the Company, net (cash) debt, working capital, copper C1 cash cost, copper C1 cash cost including foreign exchange hedges, gold C1 cash cost and gold AISC are non-IFRS measures. These measures do not have a standardized meaning prescribed by IFRS and might not be comparable to similar financial measures disclosed by other issuers. Please refer to the Company’s discussion of Non-IFRS measures in its Management’s Discussion and Analysis for the three and nine months ended September 30, 2025 and the Reconciliation of Non-IFRS Measures section at the end of this press release.

(2) Copper C1 cash cost including foreign exchange hedges was $2.25 in Q3 2025 (Q3 2024 - $1.72) for the Caraíba Operations, and $1.58 in Q3 2025 for the Tucumã Operation.

5	Ero Copper Corp
	625 Howe Street	Suite 1050	Vancouver	BC	V6C 2T6	Canada
	TSX: ERO
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NYSE: ERO

FINANCIAL HIGHLIGHTS

($ in millions, except per share amounts)

	2025 - Q3		2025 - Q2		2024 - Q3		2025 - YTD		2024 - YTD
Revenues	$	177.1	$	163.5	$	124.8	$	465.7	$	347.7
Gross profit	57.4		67.3		53.7		180.2		128.2
EBITDA(1)	90.8		114.2		74.5		322.8		56.1
Adjusted EBITDA(1)	77.1		82.7		62.2		223.0		157.0
Cash flow from operations	110.3		90.3		52.7		266.0		84.6
Net income (loss)	36.5		71.0		41.4		188.2		(18.9)
Net income (loss) attributable to owners of the Company	36.0		70.5		40.9		186.8		(19.5)
Per share (basic)	0.35		0.68		0.40		1.80		(0.19)
Per share (diluted)	0.35		0.68		0.39		1.80		(0.19)
Adjusted net income attributable to owners of the Company(1)	27.9		48.1		27.6		111.9		63.0
Per share (basic)	0.27		0.46		0.27		1.08		0.61
Per share (diluted)	0.27		0.46		0.27		1.08		0.61
Cash, cash equivalents, and short-term investments	66.3		68.3		20.2		66.3		20.2
Working deficit(1)	(45.2)		(33.5)		(60.9)		(45.2)		(60.9)
Net debt(1)	545.5		559.1		518.7		545.5		518.7

6	Ero Copper Corp
	625 Howe Street	Suite 1050	Vancouver	BC	V6C 2T6	Canada
	TSX: ERO
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NYSE: ERO

2025 PRODUCTION AND COST GUIDANCE

Consolidated copper production guidance for 2025 is maintained with overall production expected at the low end of the 67,500 to 80,000-tonne range. Production in Q4 2025 is expected to improve due to increased plant throughput at both the Caraíba and Tucumã Operations, with Tucumã also expected to benefit from mine sequencing in higher grade blocks of the open pit. At the Caraíba Operations, C1 cash costs(1) are expected to be in the lower half of the guidance range of $2.15 to $2.35 per pound of copper produced, while at Tucumã, C1 cash costs(1) are now expected to be in the range of $1.35 to $1.55 per pound (from $1.10 to $1.30 per pound previously), reflecting higher-than-expected maintenance and freight costs experienced in Q3 2025.

	Previous Guidance	Current Guidance
Copper Production (tonnes)
Caraíba Operations	37,500 - 42,500	37,500 - 42,500
Tucumã Operation	30,000 - 37,500	30,000 - 37,500
Total Copper	67,500 - 80,000	67,500 - 80,000
Copper C1 Cash Cost(1) Guidance
Caraíba Operations	$2.15 - $2.35	$2.15 - $2.35
Tucumã Operation	$1.10 - $1.30	$1.35 - $1.55
The Xavantina Operations
Au Production (ounces)	40,000 - 50,000	40,000 - 50,000
Gold C1 Cash Cost(1) Guidance	$850 - $1,000	$850 - $1,000
Gold AISC(1) Guidance	$1,800 - $2,000	$1,800 - $2,000

(1) Please refer to the section titled "Alternative Performance (Non-IFRS) Measures" within the MD&A.

7	Ero Copper Corp
	625 Howe Street	Suite 1050	Vancouver	BC	V6C 2T6	Canada
	TSX: ERO
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NYSE: ERO

2025 CAPITAL EXPENDITURE GUIDANCE

Capital expenditure guidance remains unchanged at a range of $230 to $270 million, excluding capitalized ramp-up costs prior to the declaration of commercial production at the Tucumã Operation.

Figures presented in the table below are in USD millions.

Caraíba Operations	$165 - $180
Tucumã Operation(1)	$30 - $40
Xavantina Operations	$25 - $35
Furnas Copper-Gold Project and Other Exploration	$10 - $15
Total	$230 - $270

Note: Guidance is based on certain estimates and assumptions, including but not limited to, mineral reserve estimates, grade and continuity of interpreted geological formations and metallurgical performance. Please refer to the Company’s most recent Annual Information Form and Management of Risks and Uncertainties in the MD&A for complete risk factors.

(1) Excludes capitalized ramp-up costs prior to the declaration of commercial production at the Tucumã Operation.

8	Ero Copper Corp
	625 Howe Street	Suite 1050	Vancouver	BC	V6C 2T6	Canada
	TSX: ERO
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NYSE: ERO

CONFERENCE CALL DETAILS

The Company will hold a conference call on Wednesday, November 5, 2025 at 11:30 am Eastern time (8:30 am Pacific time) to discuss these results. A results presentation will be available for download via the webcast link and in the Presentations section of the Company's website on the day of the conference call.

Date:	Wednesday, November 5, 2025
Time:	11:30 am Eastern time (8:30 am Pacific time)
Dial in:	Canada/USA Toll Free: 1-833-752-3380<br><br>International: +1-647-846-2821<br><br><br><br>Please dial in 5-10 minutes prior to the start of the call or pre-register using this link to bypass the live operator queue.<br><br><br><br>(https://dpregister.com/sreg/10202684/ffdaf70798)
Webcast:	To access the webcast, click here.<br><br>(https://event.choruscall.com/mediaframe/webcast.html?webcastid=8rQ1Un71)
Replay:	Canada/USA: 1-855-669-9658, International: +1-412-317-0088<br><br>For country-specific dial-in numbers, click here.<br><br><br><br>(https://services.choruscall.com/ccforms/replay.html)
Replay Passcode:	1606784
9	Ero Copper Corp
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	625 Howe Street	Suite 1050	Vancouver	BC	V6C 2T6	Canada
	TSX: ERO
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NYSE: ERO

Reconciliation of Non-IFRS Measures

Financial results of the Company are presented in accordance with IFRS. The Company utilizes certain alternative performance (non-IFRS) measures to monitor its performance, including copper C1 cash cost, copper C1 cash cost including foreign exchange hedges, gold C1 cash cost, gold AISC, EBITDA, adjusted EBITDA, adjusted net income attributable to owners of the Company, adjusted net income per share, net (cash) debt, working capital and available liquidity. These performance measures have no standardized meaning prescribed within generally accepted accounting principles under IFRS and, therefore, amounts presented may not be comparable to similar measures presented by other mining companies. These non-IFRS measures are intended to provide supplemental information and should not be considered in isolation or as a substitute for measures of performance prepared in accordance with IFRS.

For additional details please refer to the Company’s discussion of non-IFRS and other performance measures in its Management’s Discussion and Analysis for the three and nine months ended September 30, 2025 which is available on SEDAR+ at www.sedarplus.ca, and on EDGAR at www.sec.gov.

10	Ero Copper Corp
	625 Howe Street	Suite 1050	Vancouver	BC	V6C 2T6	Canada
	TSX: ERO
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Copper C1 cash cost and copper C1 cash cost including foreign exchange hedges

The following table provides a reconciliation of copper C1 cash cost to cost of production, its most directly comparable IFRS measure.

The Caraíba Operations

Reconciliation:	2025 - Q3		2025 - Q2		2024 - Q3		2025 - YTD		2024 - YTD
Cost of production	$	50,261	$	46,890	$	40,149	$	132,870	$	124,321
Add (less):
Transportation costs & other	1,731		1,792		1,283		4,845		3,818
Treatment, refining, and other	2,508		2,340		3,170		7,258		12,398
By-product credits	(6,693)		(6,205)		(6,584)		(17,597)		(12,455)
Incentive payments	(1,425)		(1,457)		(1,138)		(4,171)		(3,511)
Net change in inventory	199		(1,611)		(1,220)		1,247		(5,581)
Foreign exchange translation and other	(46)		16		3		(177)		17
C1 cash costs(1)	46,535		41,765		35,663		124,275		119,007
(Gain) loss on foreign exchange hedges	(1,460)		(217)		1,965		539		1,735
C1 cash costs including foreign exchange hedges	$	45,075	$	41,548	$	37,628	$	124,814	$	120,742
Mining	$	33,943	$	31,442	$	26,529	$	91,181	$	79,666
---	---	---	---	---	---	---	---	---	---	---
Processing	8,222		6,549		7,069		21,123		22,173
Indirect	8,555		7,639		5,479		22,310		17,225
Production costs	50,720		45,630		39,077		134,614		119,064
By-product credits	(6,693)		(6,205)		(6,584)		(17,597)		(12,455)
Treatment, refining and other	2,508		2,340		3,170		7,258		12,398
C1 cash costs(1)	46,535		41,765		35,663		124,275		119,007
(Gain) loss on foreign exchange hedges	(1,460)		(217)		1,965		539		1,735
C1 cash costs including foreign exchange hedges	$	45,075	$	41,548	$	37,628	$	124,814	$	120,742	11	Ero Copper Corp
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	625 Howe Street	Suite 1050	Vancouver	BC	V6C 2T6	Canada
	TSX: ERO
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NYSE: ERO
	2025 - Q3		2025 - Q2		2024 - Q3		2025 - YTD		2024 - YTD
---	---	---	---	---	---	---	---	---	---	---
Costs per pound
Total copper produced (lbs, 000)	20,030		20,199		21,871		56,448		59,257
Mining	$	1.69	$	1.56	$	1.22	$	1.62	$	1.34
Processing	$	0.41	$	0.32	$	0.32	$	0.37	$	0.38
Indirect	$	0.43	$	0.38	$	0.25	$	0.40	$	0.29
By-product credits	$	(0.33)	$	(0.31)	$	(0.30)	$	(0.31)	$	(0.21)
Treatment, refining and other	$	0.12	$	0.12	$	0.14	$	0.12	$	0.21
Copper C1 cash costs(1)	$	2.32	$	2.07	$	1.63	$	2.20	$	2.01
(Gain) loss on foreign exchange hedges	$	(0.07)	$	(0.01)	$	0.09	$	0.01	$	0.03
Copper C1 cash costs including foreign exchange hedges	$	2.25	$	2.06	$	1.72	$	2.21	$	2.04

The Tucumã Operation

Reconciliation:	2025 - Q3
Cost of production	$	18,308
Add (less):
Transportation costs & other	4,880
Treatment, refining, and other	1,486
By-product credits	—
Incentive payments	(401)
Net change in inventory	2,783
Foreign exchange translation and other	—
C1 cash costs(1)	27,056
(Gain) loss on foreign exchange hedges	(586)
C1 cash costs including foreign exchange hedges	$	26,470
Mining	$	4,552
---	---	---
Processing	12,455
Indirect	3,698
Production costs	20,705
By-product credits	—
Treatment, refining and other	6,351
C1 cash costs(1)	27,056
(Gain) loss on foreign exchange hedges	(586)
C1 cash costs including foreign exchange hedges	$	26,470		12	Ero Copper Corp
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	625 Howe Street	Suite 1050	Vancouver	BC	V6C 2T6	Canada
	TSX: ERO
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NYSE: ERO
	2025 - Q3
---	---	---
Costs per pound
Total copper produced (lbs, 000)	16,707
Mining	$	0.27
Processing	$	0.75
Indirect	$	0.22
By-product credits	$	—
Treatment, refining and other	$	0.38
Copper C1 cash costs(1)	$	1.62
(Gain) loss on foreign exchange hedges	$	(0.04)
Copper C1 cash costs including foreign exchange hedges	$	1.58

Gold C1 cash cost and gold AISC

The following table provides a reconciliation of gold C1 cash cost and gold AISC to cost of production, its most directly comparable IFRS measure.

Reconciliation:	2025 - Q3		2025 - Q2		2024 - Q3		2025 - YTD		2024 - YTD
Cost of production	$	10,032	$	8,761	$	6,220	$	25,018	$	21,055
Add (less):
Incentive payments	(364)		(209)		(378)		(842)		(1,047)
Net change in inventory	191		63		1,378		1,593		1,320
By-product credits	(208)		(159)		(232)		(478)		(680)
Smelting and refining	49		42		79		126		266
Foreign exchange translation, transportation and other	156		133		203		373		650
C1 cash costs	$	9,856	$	8,631	$	7,270	$	25,790	$	21,564
Site general and administrative	1,602		1,264		1,321		3,954		4,024
Accretion of mine closure and rehabilitation provision	151		145		82		437		262
Sustaining capital expenditure	7,307		4,435		2,784		15,651		8,691
Sustaining lease payments	2,524		2,313		1,801		6,858		5,831
Royalties and production taxes	566		511		686		1,415		2,058
AISC	$	22,006	$	17,299	$	13,944	$	54,105	$	42,430	13	Ero Copper Corp
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	625 Howe Street	Suite 1050	Vancouver	BC	V6C 2T6	Canada
	TSX: ERO
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NYSE: ERO
	2025 - Q3		2025 - Q2		2024 - Q3		2025 - YTD		2024 - YTD
---	---	---	---	---	---	---	---	---	---	---
Costs
Mining	$	4,871	$	4,552	$	3,852	$	13,183	$	11,377
Processing	2,787		2,472		2,419		7,465		6,955
Indirect	2,357		1,724		1,152		5,494		3,646
Production costs	10,015		8,748		7,423		26,142		21,978
Smelting and refining costs	49		42		79		126		266
By-product credits	(208)		(159)		(232)		(478)		(680)
C1 cash costs	$	9,856	$	8,631	$	7,270	$	25,790	$	21,564
Site general and administrative	1,602		1,264		1,321		3,954		4,024
Accretion of mine closure and rehabilitation provision	151		145		82		437		262
Sustaining capital expenditure	7,307		4,435		2,784		15,651		8,691
Sustaining leases payments	2,524		2,313		1,801		6,858		5,831
Royalties and production taxes	566		511		686		1,415		2,058
AISC	$	22,006	$	17,299	$	13,944	$	54,105	$	42,430
Costs per ounce
Total gold produced (ounces)	9,073		7,743		13,485		23,454		48,274
Mining	$	537	$	588	$	286	$	562	$	236
Processing	$	307	$	319	$	179	$	318	$	144
Indirect	$	260	$	223	$	85	$	234	$	76
Smelting and refining	$	5	$	5	$	6	$	5	$	6
By-product credits	$	(23)	$	(20)	$	(17)	$	(19)	$	(15)
Gold C1 cash cost	$	1,086	$	1,115	$	539	$	1,100	$	447
Gold AISC	$	2,425	$	2,234	$	1,034	$	2,307	$	879	14	Ero Copper Corp
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	625 Howe Street	Suite 1050	Vancouver	BC	V6C 2T6	Canada
	TSX: ERO
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NYSE: ERO

Earnings before interest, taxes, depreciation and amortization (EBITDA) and Adjusted EBITDA

The following table provides a reconciliation of EBITDA and Adjusted EBITDA to net income, its most directly comparable IFRS measure.

Reconciliation:	2025 - Q3		2025 - Q2		2024 - Q3		2025 - YTD		2024 - YTD
Net Income (Loss)	$	36,513	$	71,028	$	41,367	$	188,168	$	(18,862)
Adjustments:
Finance expense	11,331		5,976		4,039		22,030		13,238
Finance income	(1,208)		(1,130)		(781)		(3,176)		(3,610)
Income tax expense (recovery)	12,774		13,082		8,331		40,597		(1,789)
Amortization and depreciation	31,369		25,215		21,555		75,204		67,145
EBITDA	$	90,779	$	114,171	$	74,511	$	322,823	$	56,122
Foreign exchange (gain) loss	(22,055)		(38,640)		(17,246)		(119,095)		72,204
Share based compensation	6,742		7,756		4,859		15,671		17,479
Unrealized loss (gain) on commodity derivatives	1,627		(636)		(360)		3,093		12
Write-down of exploration and evaluation asset	—		—		467		—		11,212
Xavantina Gold Stream transaction fees	—		—		—		458		—
Adjusted EBITDA	$	77,093	$	82,651	$	62,231	$	222,950	$	157,029

15	Ero Copper Corp
	625 Howe Street	Suite 1050	Vancouver	BC	V6C 2T6	Canada
	TSX: ERO
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NYSE: ERO

Adjusted net income attributable to owners of the Company and Adjusted net income per share attributable to owners of the Company

Reconciliation:	2025 - Q3		2025 - Q2		2024 - Q3		2025 - YTD		2024 - YTD
Net income (loss) as reported attributable to the owners of the Company	$	35,978	$	70,548	$	40,857	$	186,753	$	(19,531)
Adjustments:
Share based compensation	6,742		7,756		4,859		15,671		17,479
Unrealized foreign exchange (gain) loss on USD denominated balances in MCSA	(15,057)		(28,204)		(11,860)		(82,889)		47,914
Unrealized foreign exchange (gain) loss on foreign exchange derivative contracts	(3,964)		(6,606)		(9,807)		(27,309)		15,503
Unrealized loss (gain) on commodity derivatives	1,574		(633)		(367)		3,020		3
Write-down of exploration and evaluation asset	—		—		465		—		11,210
Xavantina Gold Stream transaction fees	—		—		—		458		—
Tax effect on the above adjustments	2,661		5,281		3,431		16,221		(9,601)
Adjusted net income attributable to owners of the Company	$	27,934	$	48,142	$	27,578	$	111,925	$	62,977
Weighted average number of common shares
Basic	103,621,631		103,582,082		103,239,881		103,589,664		103,026,138
Diluted	104,044,755		103,905,561		103,973,827		103,941,295		103,742,304
Adjusted EPS
Basic	$	0.27	$	0.46	$	0.27	$	1.08	$	0.61
Diluted	$	0.27	$	0.46	$	0.27	$	1.08	$	0.61
16	Ero Copper Corp
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	625 Howe Street	Suite 1050	Vancouver	BC	V6C 2T6	Canada
	TSX: ERO
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NYSE: ERO

Net Debt (Cash)

The following table provides a calculation of net debt (cash) based on amounts presented in the Company’s condensed consolidated interim financial statements as at the periods presented.

	September 30, 2025		June 30, 2025		December 31, 2024		September 30, 2024
Current portion of loans and borrowings	$	50,590	$	58,076	$	45,893	$	39,383
Long-term portion of loans and borrowings	561,146		569,300		556,296		499,527
Less:
Cash and cash equivalents	(66,257)		(68,303)		(50,402)		(20,229)
Short-term investments	—		—		—		—
Net debt (cash)	$	545,479	$	559,073	$	551,787	$	518,681

Working Capital and Available Liquidity

The following table provides a calculation for these based on amounts presented in the Company’s condensed consolidated interim financial statements as at the periods presented.

	September 30, 2025		June 30, 2025		December 31, 2024		September 30, 2024
Current assets	$	207,413	$	178,524	$	141,790	$	126,808
Less: Current liabilities	(252,579)		(212,010)		(211,706)		(187,708)
Working deficit	$	(45,166)	$	(33,486)	$	(69,916)	$	(60,900)
Cash and cash equivalents	66,257		68,303		50,402		20,229
Available undrawn revolving credit facilities(1)	45,000		45,000		15,000		80,000
Available undrawn prepayment facilities(2)	—		—		25,000		25,000
Available liquidity	$	111,257	$	113,303	$	90,402	$	125,229

(1) In January 2025, the Company amended its Senior Credit Facility to increase the limit from $150.0 million to $200.0 million and extended the maturity from December 2026 to December 2028.

(2) In March 2025, the Company exercised its option to increase the size of its copper prepayment facility from $50.0 million to $75.0 million.

17	Ero Copper Corp
	625 Howe Street	Suite 1050	Vancouver	BC	V6C 2T6	Canada
	TSX: ERO
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NYSE: ERO

ABOUT ERO COPPER CORP

Ero Copper is a high-margin, high-growth copper and gold producer with operations in Brazil and corporate headquarters in Vancouver, B.C. The Company's primary asset is a 99.6% interest in the Brazilian copper mining company, Mineração Caraíba S.A. ("MCSA"), owner of the Company's Caraíba Operations, which are located in the Curaçá Valley, Bahia State, Brazil, and the Tucumã Operation, an open pit copper mine located in Pará State, Brazil. The Company also owns 97.6% of NX Gold S.A. ("NX Gold") which owns the Xavantina Operations, an operating gold mine located in Mato Grosso State, Brazil. In July 2024, the Company signed a definitive earn-in agreement with Vale Base Metals for the right to acquire a 60% interest in the Furnas Copper-Gold Project, located in the Carajás Mineral Province in Pará State, Brazil. For more information on the earn-in agreement, please see the Company's press releases dated October 30, 2023 and July 22, 2024. Additional information on the Company and its operations, including technical reports on the Caraíba Operations, Xavantina Operations, Tucumã Operation and the Furnas Copper-Gold Project, can be found on the Company’s website (www.erocopper.com), on SEDAR+ (www.sedarplus.ca/landingpage/) and on EDGAR (www.sec.gov). The Company’s shares are publicly traded on the Toronto Stock Exchange and the New York Stock Exchange under the symbol “ERO”.

FOR MORE INFORMATION, PLEASE CONTACT

Farooq Hamed, VP, Investor Relations

info@erocopper.com

18	Ero Copper Corp
	625 Howe Street	Suite 1050	Vancouver	BC	V6C 2T6	Canada
	TSX: ERO
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NYSE: ERO

CAUTION REGARDING FORWARD LOOKING INFORMATION AND STATEMENTS

This press release contains “forward-looking statements” within the meaning of the United States Private Securities Litigation Reform Act of 1995 and “forward-looking information” within the meaning of applicable Canadian securities legislation (collectively, “forward-looking statements”). Forward-looking statements include statements that use forward-looking terminology such as “may”, “could”, “would”, “will”, “should”, “intend”, “target”, “plan”, “expect”, “budget”, “estimate”, “forecast”, “schedule”, “anticipate”, “believe”, “continue”, “potential”, “view” or the negative or grammatical variation thereof or other variations thereof or comparable terminology. Forward-looking statements may include, but are not limited to, statements with respect to the Company's expected development and mining rates, production, operating costs and capital expenditures at the Caraíba Operations, the Tucumã Operation and the Xavantina Operations; estimated timing for certain milestones; the estimated timelines for conducting and completing the phases of work pursuant to the Furnas Copper-Gold Project definitive earn-in agreement; the estimation of mineral reserves and mineral resources; the discovery of additional mineralization and the potential for positive impacts on production rates from the mines or processing facilities; the significance of any particular exploration program or result (including the Company's expectations associated with the stockpiled gold concentrates at the Xavantina Operations) and the successful development of new deposits; the Company's ability to monetize gold concentrates produced at the Xavantina Operations, including expectations for operating costs, payability, the actual grades of gold concentrates sold, statements with respect to total volume or tonnes of gold concentrate to be sold, and the timing therein, as well as the Company’s expectations for current and future exploration plans including, but not limited to, planned areas of additional exploration and the potential to convert any portion of the inferred mineral resource base to economically viable mineral reserves; and any other statement that may predict, forecast, indicate or imply future plans, intentions, levels of activity, results, performance or achievements.

Forward-looking statements are subject to a variety of known and unknown risks, uncertainties and other factors that could cause actual results, actions, events, conditions, performance or achievements to materially differ from those expressed or implied by the forward-looking statements, including, without limitation, risks discussed in this press release and in the Company’s most recent Annual Information Form (“AIF”) under the heading “Risk Factors”. The risks discussed in this press release and in the AIF are not exhaustive of the factors that may affect any of the Company’s forward-looking statements. Although the Company has attempted to identify important factors that could cause actual results, actions, events, conditions, performance or achievements to differ materially from those contained in forward-looking statements, there may be other factors that cause results, actions, events, conditions, performance or achievements to differ from those anticipated, estimated or intended.

The Company’s forward-looking statements are based on the assumptions, beliefs, expectations and opinions of management on the date the statements are made, many of which may be difficult to predict and beyond the Company’s control. In connection with the forward-looking statements contained in this press release and in the AIF, the Company has made certain assumptions about, among other things: favourable equity and debt capital markets; the ability to raise any necessary additional capital on reasonable terms to advance the production, development and exploration of the Company’s properties and assets; future prices of copper, gold and other metal prices; the timing and results of exploration and drilling programs; the accuracy of any mineral reserve and mineral resource estimates; the geology of the Caraíba Operations, the Xavantina Operations, the Tucumã Operation and the Furnas Copper-Gold Project being as described in the respective technical report for each property; production costs; the accuracy of budgeted exploration, development and construction costs and expenditures; the price of other commodities such as fuel; future currency exchange rates, interest rates and tariff rates; operating conditions being favourable such that the Company is able to operate in a safe, efficient and effective manner; work force continuing to remain healthy in the face of prevailing epidemics, pandemics or other health risks, political and regulatory stability; the receipt of governmental, regulatory and third party approvals, licenses and permits on favourable terms; obtaining required renewals for existing approvals, licenses and permits on favourable terms; requirements under applicable laws; sustained labour stability; stability in financial and capital goods markets; availability of equipment; positive relations with local groups and the Company’s ability to meet its obligations under its agreements with such groups; and satisfying the terms and conditions of the Company’s current loan arrangements. Although the Company believes that the assumptions inherent in forward-looking statements are reasonable as of the date of this press release, these assumptions are subject to significant business, social, economic, political, regulatory, competitive and other risks and uncertainties, contingencies and other factors that could cause actual actions, events, conditions, results, performance or achievements to be materially different from those projected in the forward-looking statements. The Company cautions that the foregoing list of assumptions is not exhaustive. Other events or circumstances could cause actual results to differ materially from those estimated or projected and expressed in, or implied by, the forward-looking statements contained in this press release. There can be no assurance that forward-looking statements will prove to be accurate, as actual results and future events could differ materially from those anticipated in such statements. Accordingly, readers should not place undue reliance on forward-looking statements.

Forward-looking statements contained herein are made as of the date of this press release and the Company disclaims any obligation to update or revise any forward-looking statement, whether as a result of new information, future events or results or otherwise, except as and to the extent required by applicable securities laws.

CAUTIONARY NOTES REGARDING MINERAL RESOURCE AND MINERAL RESERVE ESTIMATES

Unless otherwise indicated, all reserve and resource estimates included in this press release and the documents incorporated by reference herein have been prepared in accordance with National Instrument 43-101, Standards of Disclosure for Mineral Projects (“NI 43-101") and the Canadian Institute of Mining, Metallurgy and Petroleum (the “CIM”) — CIM Definition Standards on Mineral Resources and Mineral Reserves, adopted by the CIM Council, as amended (the “CIM Standards”). NI 43-101 is a rule developed by the Canadian Securities Administrators that establishes standards for all public disclosure an issuer makes of scientific and technical information concerning mineral projects. Canadian standards, including NI 43-101, differ significantly from the requirements of the United States Securities and Exchange Commission (the “SEC”), and reserve and resource information included herein may not be comparable to similar information disclosed by U.S. companies. In particular, and without limiting the generality of the foregoing, this press release and the documents incorporated by reference herein use the terms “measured resources,” “indicated resources” and “inferred resources” as defined in accordance with NI 43-101 and the CIM Standards.

19	Ero Copper Corp
	625 Howe Street	Suite 1050	Vancouver	BC	V6C 2T6	Canada