Supplementary prospectus to £3,000,000,000 Euro Medium Term Note Programme

Issuer LEI: 213800ZBKL9BHSL2K459

OSB GROUP PLC

(the "Company” or "Issuer”)

The Company announces today that a supplementary prospectus dated 23 August 2023 to the base prospectus dated 5 April 2023 (the "Base Prospectus"), in relation to the establishment of its £3,000,000,000 Euro Medium Term Note Programme (the "EMTN Programme”) has been approved by the Financial Conduct Authority and is available for viewing.

To view the full document, paste the following URL into the address bar of your browser:

https://www.osb.co.uk/investors/debt-investors/emtn-programme/

A copy of the supplementary prospectus will also be submitted to the National Storage Mechanism and will shortly be available for inspection at: https://data.fca.org.uk/#/nsm/nationalstoragemechanism.

OSB GROUP PLC

Alastair Pate                                                 t: +44 0771 418 1864
Group Head of Investor Relations

Jens Bech
Group Commercial Director                                    t: +44 0774 024 7473

Notes to Editors

About OSB Group PLC

OSB began trading as a bank on 1 February 2011 and was admitted to the main market of the London Stock Exchange in June 2014 (OSB.L). OSB joined the FTSE 250 index in June 2015. On 4 October 2019, OSB acquired Charter Court Financial Services Group plc (CCFS) and its subsidiary businesses. On 30 November 2020, OSB GROUP PLC became the listed entity and holding company for the OSB Group. OSB is a specialist lending and retail savings Group authorised by the Prudential Regulation Authority, part of the Bank of England, and regulated by the Financial Conduct Authority and Prudential Regulation Authority. The Group reports under two segments, OneSavings Bank and Charter Court Financial Services.