OSB GROUP PLC announces Indicative Results of its Tender Offers for its £300,000,000 Fixed Rate Resetting Notes due 7 September 2028 and £400,000,000 Fixed Rate Resetting Notes due 16 January 2030

OSB GROUP PLC announces Indicative Results of its Tender Offers for its

£300,000,000 Fixed Rate Resetting Notes due 7 September 2028 and £400,000,000 Fixed Rate Resetting Notes due 16 January 2030

THIS ANNOUNCEMENT RELATES TO THE DISCLOSURE OF INFORMATION THAT QUALIFIED OR MAY HAVE QUALIFIED AS INSIDE INFORMATION FOR THE PURPOSES OF ARTICLE 7 OF THE MARKET ABUSE REGULATION (EU) 596/2014 AS IT FORMS PART OF UK DOMESTIC LAW BY VIRTUE OF THE EUROPEAN UNION (WITHDRAWAL) ACT 2018 (the EUWA).

NOT FOR RELEASE, PUBLICATION OR DISTRIBUTION IN OR INTO OR TO ANY PERSON LOCATED OR RESIDENT, OR TO ANY ADDRESS, IN THE UNITED STATES OF AMERICA, ITS TERRITORIES AND POSSESSIONS (INCLUDING PUERTO RICO, THE U.S. VIRGIN ISLANDS, GUAM, AMERICAN SAMOA, WAKE ISLAND AND THE NORTHERN MARIANA ISLANDS), ANY STATE OF THE UNITED STATES OF AMERICA OR THE DISTRICT OF COLUMBIA (the United States) OR IN OR INTO OR TO ANY PERSON LOCATED OR RESIDENT IN ANY OTHER JURISDICTION WHERE OR TO WHOM IT IS UNLAWFUL TO RELEASE, PUBLISH OR DISTRIBUTE THIS ANNOUNCEMENT.

13 November 2026. OSB GROUP PLC (the Offeror) announces today the indicative (non-binding) results of its separate invitations to holders of its outstanding: (i) £300,000,000 Fixed Rate Resetting Notes due 7 September 2028 (ISIN: XS2642668821) (the 2028 Notes); and (ii) £400,000,000 Fixed Rate Resetting Notes due 16 January 2030 (ISIN: XS2747270986) (the 2030 Notes and, together with the 2028 Notes, the Notes and each a Series) to tender their Notes for purchase by the Offeror for cash (each such invitation, an Offer, and together, the Offers).

The Offers were announced on 5 November 2026 and were made on the terms and subject to the conditions contained in the tender offer memorandum dated 5 November 2026 (the Tender Offer Memorandum) prepared by the Offeror in connection with the Offers. Capitalised terms used but not otherwise defined in this announcement shall have the meanings given to them in the Tender Offer Memorandum.

Expiration Deadline

The Expiration Deadline for the Offers was 4.00 p.m. (London time) on 12 November 2026.

As at the Expiration Deadline, the Offeror had received valid tenders for purchase pursuant to the Offers of (i) £279,585,000 in aggregate principal amount of the 2028 Notes; and (ii) £354,849,000 in aggregate principal amount of the 2030 Notes.

Expected Series Acceptance Amounts

If the Offeror decides to accept Notes for purchase pursuant to the relevant Offer(s), the level at which it expects to set the Final Acceptance Amount is £634,434,000. Accordingly, the levels at which the Offeror expects to set each Series Acceptance Amount are as follows:

Noteholders should note that this is a non-binding indication of the levels at which the Offeror expects to set each Series Acceptance Amount.

Pricing for the Offers is expected to take place at around 11.00 a.m. (London time) (the Pricing Time) today. As soon as reasonably practicable after the Pricing Time, the Offeror intends to announce whether it will accept any valid tenders of Notes pursuant to either or both of the Offers and, if so accepted, the Final Acceptance Amount, each Series Acceptance Amount, each Benchmark Security Rate, each Purchase Yield, each Purchase Price and the aggregate principal amount of each Series that will remain outstanding after the Settlement Date.

The Settlement Date in respect of the Notes accepted for purchase pursuant to the Offers is expected to be 16 November 2026.

Jefferies International Limited (Attention: Liability Management EMEA; Telephone: +44 20 7029 8000; Email: liabilitymanagement@jefferies.com) and Morgan Stanley & Co. International plc (Attention: Liability Management Team, Global Capital Markest; Telephone: +44 20 7425 5695; Email: liabilitymanagementeurope@morganstanley.com) and Kroll Issuer Services Limited (Attention: Owen Morris; Telephone: +44 20 7704 0880; Email: osb@is.kroll.com).

DISCLAIMER The offer period for the Offers has now expired. No further tenders of Notes may be made pursuant to the Offers. This announcement must be read in conjunction with the Tender Offer Memorandum. No offer or invitation to acquire any securities is being made pursuant to this announcement. The distribution of this announcement, the Tender Offer Memorandum and/or any other materials relating to the Offers in certain jurisdictions may be restricted by law. Persons into whose possession this announcement, the Tender Offer Memorandum and/or any other materials relating to the Offers come are required by each of the Offeror, the Dealer Managers and the Tender Agent to inform themselves about, and to observe, any such restrictions.