6-K

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, DC 20549

FORM 6-K

REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16

UNDER THE SECURITIES EXCHANGE ACT OF 1934

April 3, 2023

Commission File Number 1-10167

WESTPAC BANKING CORPORATION

(Translation of registrant’s name into English)

275 KENT STREET, SYDNEY, NEW SOUTH WALES 2000, AUSTRALIA

(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.

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): ¨

Incorporation by Reference

The information contained in this Report on Form 6-K, excluding the information set forth in Exhibit No. 1, shall be incorporated by reference in the prospectuses relating to the Registrant’s securities contained in the Registrant’s Registration Statements on Form F-3 (File Nos. 333-260702 and 333-260703), as such prospectuses may be amended or supplemented from time to time.

Westpac Completes the Merger of BTSuper and Sale of Advance to Mercer

On April 3, 2023, Westpac announced that it had completed the previously announced merger of BT’s personal and corporate superannuation funds with Mercer Super Trust and the sale of its Advance Asset Management (Advance) business to Mercer Australia. The merger and sale were first announced on May 26, 2022.

Westpac expects to report an after-tax gain on the sale of Advance that will be disclosed as a notable item. The completion of the sale and merger adds approximately 8 basis points to Westpac’s common equity Tier 1 capital ratio^1^.

Index to Exhibits

Disclosure regarding forward-looking statements

The information contained in this Report on Form 6-K contains statements that constitute “forward-looking statements” within the meaning of section 21E of the U.S. Securities Exchange Act of 1934.

Forward-looking statements are statements about matters that are not historical facts. Forward-looking statements appear in a number of places in this Report and include statements regarding our intent, belief or current expectations with respect to our business and operations, macro and micro economic and market conditions, results of operations and financial condition, capital adequacy and risk management, including, without limitation, future loan loss provisions and financial support to certain borrowers, forecasted economic indicators and performance metric outcomes, indicative drivers, climate- and other sustainability-related statements, commitments, targets, projections and metrics, and other estimated and proxy data.

^1^ On a pro forma December 31, 2022 basis.

We use words such as ‘will’, ‘may’, ‘expect’, ‘intend’, ‘seek’, ‘would’, ‘should’, ‘could’, ‘continue’, ‘plan’, ‘estimate’, ‘anticipate’, ‘believe’, ‘probability’, ‘indicative’, ‘risk’, ‘aim’, ‘outlook’, ‘forecast’, ‘f’cast’, ‘f’, ‘assumption’, ‘projection’, ‘target’, ‘goal’, ‘guidance’, ‘ambition’, or other similar words to identify forward-looking statements, or otherwise identify forward-looking statements. These forward-looking statements reflect our current views on future events and are subject to change, certain known and unknown risks, uncertainties and assumptions and other factors which are, in many instances, beyond our control (and the control of our officers, employees, agents and advisors), and have been made based on management’s expectations or beliefs concerning future developments and their potential effect upon us. Forward-looking statements may also be made, verbally or in writing, by members of Westpac’s management or Board in connection with this Report. Such statements are subject to the same limitations, uncertainties, assumptions and disclaimers set out in this Report.

There can be no assurance that future developments or performance will align with our expectations or that the effect of future developments on us will be those anticipated. Actual results could differ materially from those we expect or which are expressed or implied in forward-looking statements, depending on various factors including, but not limited to, those described in the section titled ‘Risk factors’ under the section ‘Risk and risk management’ in Westpac’s 2022 Annual Report on Form 20-F filed with the U.S. Securities and Exchange Commission. When relying on forward-looking statements to make decisions with respect to us, investors and others should carefully consider such factors and other uncertainties and events.

Except as required by law, we assume no obligation to revise or update any forward-looking statements contained in this Report, whether from new information, future events, conditions or otherwise, after the date of this Report.

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.

Exhibit 1

ASX Release 3 April 2023Level 18, 275 Kent Street Sydney, NSW, 2000WESTPAC COMPLETES THE MERGER OF BT SUPER AND SALE OF ADVANCE TO MERCERWestpac has completed the previously announced merger of BT’s personal and corporate superannuation funds with Mercer Super Trust and the sale of its Advance Asset Management (Advance) business to Mercer Australia. The merger and sale were first announced on 26 May 2022.Westpac expects to report an after-tax gain on the sale of Advance that will be disclosed as a notable item. The completion of the sale and merger adds approximately 8 basis points to Westpac’s common equity Tier 1 capital ratio1.Westpac Specialist Businesses Chief Executive, Jason Yetton, said “Since the formation of Specialist Businesses Division in May 2020, we have announced and completed nine business divestments and as a result, Westpac is now a much simpler, stronger bank.“The completion of the merger and sale has created benefits for BT Super members, new opportunities for our people with a global investment and retirement specialist, and redefined the landscape of superannuation in Australia,” Mr Yetton said.BT Super Trustee Chair, Gai McGrath said “Mercer Super has been helping Australians with their retirement for more than 25 years and is well placed to support BT Super members and participating employers. This merger has created a larger superannuation fund with the potential to deliver improved performance, lower fees, and broader member services, while maintaining continuity of knowledge and service for BT Super members.”The merged fund manages approximately $63 billion in assets and helps more than 850,000 Australians prepare for retirement2.For further information:Lisa Parrett Justin McCarthy Media Relations General Manager, Investor Relations 0432 933 796 0422 800 321This document has been authorised for release by Tim Hartin, Company Secretary.1 On a pro forma 31 December 2022 basis 2 Assets under management as at 31 December 2022 for BT Super and Mercer Super on a combined basis