LONDON–(BUSINESS WIRE)– As Agent Bank, please be advised of the following rate determined on: 9/17/2026 Issue ¦ Westpac Banking Corporation Series No 1597 GBP 100,000,000 FRN due March 2027 ISIN Number ¦ XS3325371642 ISIN Reference ¦ 332537164 Issue Nomin GBP ¦ 100000000 Period ¦ 6/24/2026 to 9/24/2026 Payment Date 9/24/2026 Number of Days ¦ 92 Rate ¦ 4.1478 Denomination GBP ¦ 100000 ¦ 100000000 ¦ Amount Payable per Denomination ¦ 1045.47 ¦ 1045470 ¦ Bank of New Y