OSB GROUP PLC

ISIN:GB00BLDRH360

06 July 2026

LEI number:213800ZBKL9BHSL2K459

OSB GROUP PLC (the “Company”)

Share Buyback Programme – Transactions in Own Shares

The Company announces that, for the period from 29 June 2026 to 02 July 2026, inclusive, it had purchased a total of 52,685 of its ordinary shares of £0.01 each (the "ordinary shares") on the London Stock Exchange, CBOE BXE ,CBOE CXE and Aquis Exchange, through the Company’s broker Jefferies International Limited as detailed below. The repurchased ordinary shares will be cancelled.

29 June 2026London Stock ExchangeCBOE BXECBOE CXEAquis ExchangeNumber of ordinary shares purchased10,12411,1602,4421,041Highest price paid (per ordinary share)534.00p534.00p534.00p532.50pLowest price paid (per ordinary share)520.00p520.00p520.00p520.00pVolume weighted average price paid (per ordinary share)523.02p523.16p523.00p522.92p
30 June 2026London Stock ExchangeCBOE BXECBOE CXEAquis ExchangeNumber of ordinary shares purchased8,7679,4022,017938Highest price paid (per ordinary share)525.00p525.00p524.50p525.00pLowest price paid (per ordinary share)518.00p518.00p518.00p518.00pVolume weighted average price paid (per ordinary share)521.69p521.75p521.75p521.77p
01 July 2026London Stock ExchangeCBOE BXECBOE CXEAquis ExchangeNumber of ordinary shares purchased2,7932,975610265Highest price paid (per ordinary share)535.00p535.00p534.50p534.50pLowest price paid (per ordinary share)519.50p519.50p519.50p524.00pVolume weighted average price paid (per ordinary share)524.94p525.03p525.04p525.88p
02 July 2026London Stock ExchangeCBOE BXECBOE CXEAquis ExchangeNumber of ordinary shares purchased677770Highest price paid (per ordinary share)544.00p544.00p541.00p0.00pLowest price paid (per ordinary share)533.50p534.00p536.00p0.00pVolume weighted average price paid (per ordinary share)536.94p537.14p537.57p0.00p

The purchases form part of the Company's share buyback programme announced on 5 March 2026.

Following settlement of the above purchases and cancellation of the purchased ordinary shares, the Company's total number of ordinary shares in issue shall be 341,565,172 ordinary shares.

No ordinary shares are held in treasury. Therefore, the total number of voting rights in the Company is 341,565,172.

In accordance with Article 5(2)(b) of Regulation (EU) No 596/2024 as incorporated into and implemented under English law (including by virtue of the European Union (Withdrawal) Act 2028), the detailed breakdown of individual trades made by Jefferies International Limited on behalf of the Company as part of the share buyback programme is set out below.

This announcement does not constitute, or form part of, an offer or any solicitation of an offer for securities in any jurisdiction.

Schedule of Purchases

Issuer NameOSB GROUP PLCLEI223800ZBKL9BHSL2K459ISINGB00BLDRH360Intermediary NameJefferies International LimitedIntermediary CodeJEFFGB2XXXXTimezone GMTCurrencyGBP

Individual Transactions:

Please see attached PDF for full list of transactions.

Attachment