6-K

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 of the Securities Exchange Act of 1934

For the month of August 2025

Commission File Number: 001-42757

BRBI BR Partners S.A.

(Exact Name as Specified in its Charter)

N/A

(Translation of registrant’s name into English)

3,732, Floor 28, CEP 04538-132

Avenida Brigadeiro Faria Lima

São Paulo, SP, Brazil

(Address of principal executive offices)

(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: ☐

EXHIBIT INDEX

1

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.

Date: August 29, 2025

2

Exhibit 99.1

BRBI BR PARTNERS S.A.

CNPJ/MF No. 10.739.356/0001-03

Brigadeiro Faria Lima Avenue, 3,732, 28th floor

Zip Code 04538-132, São Paulo, SP

CVM Code: 2586-0

MATERIAL FACT

BRBI BR PARTNERS S.A. (“Company”) (B3: BRBI11), in compliance with the Brazilian Securities and Exchange Commission (CVM) Resolution No. 44, informs its shareholders and the market in general that, on this date, BR Partners Holdco Participações S.A. (“Holdco”), the Company’s direct controlling shareholder, completed an intragroup corporate reorganization, which resulted in the partial spin-off of the Company shareholding to a new holding company named Black River Holdings e Investimentos Ltda. (“Black River”), a company fully controlled by Mr. Ricardo Fleury Cavalcanti de Albuquerque Lacerda, the Company’s indirect shareholder (“Holdco Reorganization”).

As a result of the Holdco Reorganization, Black River became the holder of 81,924,944 common shares issued by the Company, representing 40.85% of the Company’s total common shares and 26.1% of the total capital, whereas Holdco remained as the holder of 71,383,183 common shares and 19,964,814 preferred shares, representing 35.59% of the common shares, 17.45% of the preferred shares, and 29.0% of the Company’s total capital. In order to regulate the exercise of voting rights and the transfer of shares issued by the Company held by them, Holdco and Black River, on this date, entered into a shareholders’ agreement (“Shareholders’ Agreement”), which in compliance with CVM Resolution 80, is available for consultation on the Company’s website (ri.brpartners.com.br/en/corporate-governance/policies/), on CVM’s website (gov.br/cvm), and on B3’s website (b3.com.br).

The Company clarifies that the Holdco Reorganization does not entail any changes in the Company’s structure control, which remains exercised by the same control group, through Holdco, in accordance with the governance rules of its partnership, now also including Black River, in accordance with the Shareholders’ Agreement. The Holdco Reorganization also does not entail any impact on governance, operations, administrative structure or the business strategy of the Company and its subsidiaries.

São Paulo, August 29^th^, 2025.

BRBI BR PARTNERS S.A.

Vinicius Carmona Cardoso

Investor Relations Director