OSB GROUP PLC - Transaction in Own Shares

OSB GROUP PLC
ISIN: GB00BLDRH360
26 May 2026

LEI number: 213800ZBKL9BHSL2K459

OSB GROUP PLC (the “Company”)
Share Buyback Programme – Transactions in Own Shares

The Company announces that, for the period from 18 May 2026 to 22 May 2026, inclusive, it had purchased a total of 1,477,945 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.

18 May 2026	London Stock Exchange	CBOE BXE	CBOE CXE	Aquis Exchange
Number of ordinary shares purchased	122,586	143,651	34,152	16,903
Highest price paid (per ordinary share)	498.60p	498.60p	498.60p	498.60p
Lowest price paid (per ordinary share)	487.20p	487.40p	487.20p	487.20p
Volume weighted average price paid (per ordinary share)	492.89p	492.89p	492.89p	492.95p

19 May 2026	London Stock Exchange	CBOE BXE	CBOE CXE	Aquis Exchange
Number of ordinary shares purchased	119,484	140,194	33,433	16,476
Highest price paid (per ordinary share)	501.00p	500.50p	500.50p	500.50p
Lowest price paid (per ordinary share)	491.60p	492.00p	492.20p	492.00p
Volume weighted average price paid (per ordinary share)	496.63p	496.64p	496.64p	496.64p

20 May 2026	London Stock Exchange	CBOE BXE	CBOE CXE	Aquis Exchange
Number of ordinary shares purchased	118,506	139,049	33,157	16,358
Highest price paid (per ordinary share)	501.00p	501.00p	501.50p	501.00p
Lowest price paid (per ordinary share)	489.40p	489.40p	489.40p	489.40p
Volume weighted average price paid (per ordinary share)	494.26p	494.25p	494.28p	494.28p

21 May 2026	London Stock Exchange	CBOE BXE	CBOE CXE	Aquis Exchange
Number of ordinary shares purchased	109,289	119,558	32,709	14,903
Highest price paid (per ordinary share)	504.50p	504.50p	504.50p	504.00p
Lowest price paid (per ordinary share)	494.00p	494.40p	494.40p	497.40p
Volume weighted average price paid (per ordinary share)	500.89p	500.89p	500.92p	500.94p

22 May 2026	London Stock Exchange	CBOE BXE	CBOE CXE	Aquis Exchange
Number of ordinary shares purchased	108,951	111,917	31,102	15,567
Highest price paid (per ordinary share)	503.00p	502.50p	502.00p	501.50p
Lowest price paid (per ordinary share)	496.00p	496.00p	496.00p	496.00p
Volume weighted average price paid (per ordinary share)	499.70p	499.60p	499.56p	499.52p

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 344,548,228 ordinary shares.

No ordinary shares are held in treasury. Therefore, the total number of voting rights in the Company is 344,548,228.

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 Name	OSB GROUP PLC
LEI	223800ZBKL9BHSL2K459
ISIN	GB00BLDRH360
Intermediary Name	Jefferies International Limited
Intermediary Code	JEFFGB2XXXX
Timezone	GMT
Currency	GBP

Individual Transactions:

Please see attached PDF for full list of transactions.

Attachment

• 2026.05.22_OSBG Buyback Fills