Transaction in own shares

OSB GROUP PLC                                        
ISIN: GB00BLDRH360
24 September 2025

LEI number: 213800ZBKL9BHSL2K459

OSB GROUP PLC (the “Company”)
Transaction in Own Shares

The Company announces that on 23 September 2025 it had purchased a total of 17,683 of its ordinary shares of £0.01 each (the "ordinary shares") on the London Stock Exchange, CBOE BXE and CBOE CXE, through the Company's broker Citigroup Global Markets Limited as detailed below. The repurchased ordinary shares will be cancelled.

	London Stock Exchange	CBOE BXE	CBOE CXE
Number of ordinary shares purchased	17,683	-	-
Highest price paid (per ordinary share)	551.00p	-	-
Lowest price paid (per ordinary share)	545.50p	-	-
Volume weighted average price paid (per ordinary share)	548.00p	-	-

The purchases form part of the Company’s share buyback programme announced on 13 March 2025.

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 360,303,693 ordinary shares.

No ordinary shares are held in treasury. Therefore, the total number of voting rights in the Company is 360,303,693.

In accordance with Article 5(1)(b) of Regulation (EU) No 596/2014 as incorporated into and implemented under English law (including by virtue of the European Union (Withdrawal) Act 2018), the detailed breakdown of individual trades made by Citigroup Global Markets 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 – Individual Transactions

Issuer Name	OSB GROUP PLC
LEI	213800ZBKL9BHSL2K459
ISIN	GB00BLDRH360
Intermediary Name	Citigroup Global Markets Limited
Intermediary Code	SBILGB2L
Timezone	GMT+1
Currency	GBP

Transaction Date	Trade Time	Currency	Volume	Price	Trading Venue	Transaction ID
23-09-2025	16:27:12	GBp	255	547.00	XLON	xeaNhF1ZuJX
23-09-2025	16:27:12	GBp	384	547.00	XLON	xeaNhF1ZuJZ
23-09-2025	16:16:48	GBp	747	546.50	XLON	xeaNhF1ZgeS
23-09-2025	16:15:37	GBp	232	547.00	XLON	xeaNhF1Zh2L
23-09-2025	16:01:21	GBp	562	547.00	XLON	xeaNhF1ZRxC
23-09-2025	15:51:24	GBp	394	547.50	XLON	xeaNhF1ZFKG
23-09-2025	15:51:24	GBp	31	547.50	XLON	xeaNhF1ZFKI
23-09-2025	15:45:19	GBp	471	547.50	XLON	xeaNhF0Srh7
23-09-2025	15:42:56	GBp	818	547.00	XLON	xeaNhF0SmDH
23-09-2025	15:39:14	GBp	232	548.00	XLON	xeaNhF0SzTa
23-09-2025	15:35:18	GBp	171	548.00	XLON	xeaNhF0SdZP
23-09-2025	15:35:18	GBp	53	548.00	XLON	xeaNhF0SdZR
23-09-2025	15:31:22	GBp	219	548.00	XLON	xeaNhF0SZQ3
23-09-2025	15:04:27	GBp	431	547.50	XLON	xeaNhF0SAtb
23-09-2025	15:04:27	GBp	276	547.00	XLON	xeaNhF0SAtZ
23-09-2025	14:58:50	GBp	463	548.00	XLON	xeaNhF0TmUE
23-09-2025	14:44:00	GBp	32	548.00	XLON	xeaNhF0TeU$
23-09-2025	14:44:00	GBp	397	548.00	XLON	xeaNhF0TeUz
23-09-2025	14:43:36	GBp	291	548.50	XLON	xeaNhF0Tf6s
23-09-2025	14:43:36	GBp	99	548.50	XLON	xeaNhF0Tf6x
23-09-2025	14:43:36	GBp	225	548.50	XLON	xeaNhF0Tf6z
23-09-2025	14:26:18	GBp	392	547.00	XLON	xeaNhF0TCR@
23-09-2025	14:14:41	GBp	436	546.00	XLON	xeaNhF0U$I2
23-09-2025	14:08:00	GBp	357	546.50	XLON	xeaNhF0UdJK
23-09-2025	13:50:16	GBp	360	546.00	XLON	xeaNhF0UKOP
23-09-2025	13:45:09	GBp	295	546.50	XLON	xeaNhF0UUjH
23-09-2025	13:34:29	GBp	362	545.50	XLON	xeaNhF0U5Bc
23-09-2025	13:32:01	GBp	601	546.00	XLON	xeaNhF0U0mv
23-09-2025	13:12:01	GBp	697	546.00	XLON	xeaNhF0Vwbz
23-09-2025	12:48:50	GBp	1	545.50	XLON	xeaNhF0VMwI
23-09-2025	12:48:50	GBp	206	545.50	XLON	xeaNhF0VMwK
23-09-2025	12:33:23	GBp	297	545.50	XLON	xeaNhF0VO0E
23-09-2025	12:02:12	GBp	276	546.00	XLON	xeaNhF0OweQ
23-09-2025	11:46:54	GBp	455	546.00	XLON	xeaNhF0OisN
23-09-2025	11:25:33	GBp	305	546.50	XLON	xeaNhF0ORc0
23-09-2025	11:25:13	GBp	34	547.00	XLON	xeaNhF0ORtE
23-09-2025	11:25:13	GBp	319	547.00	XLON	xeaNhF0ORtG
23-09-2025	10:57:54	GBp	303	549.00	XLON	xeaNhF0PmWz
23-09-2025	10:45:02	GBp	402	550.00	XLON	xeaNhF0Pc1B
23-09-2025	10:38:00	GBp	416	550.50	XLON	xeaNhF0PWq$
23-09-2025	10:38:00	GBp	772	550.50	XLON	xeaNhF0PWqD
23-09-2025	10:32:51	GBp	258	551.00	XLON	xeaNhF0Pi1T
23-09-2025	10:32:51	GBp	51	551.00	XLON	xeaNhF0Pi1V
23-09-2025	09:25:07	GBp	388	550.00	XLON	xeaNhF0QaOi
23-09-2025	09:20:23	GBp	352	550.50	XLON	xeaNhF0QXze
23-09-2025	09:20:23	GBp	101	550.50	XLON	xeaNhF0QXzg
23-09-2025	09:12:46	GBp	738	551.00	XLON	xeaNhF0Qecq
23-09-2025	08:27:46	GBp	199	550.50	XLON	xeaNhF0Rn7q
23-09-2025	08:27:30	GBp	410	551.00	XLON	xeaNhF0RnEd
23-09-2025	08:04:15	GBp	459	550.50	XLON	xeaNhF0RMj4
23-09-2025	08:04:11	GBp	658	551.00	XLON	xeaNhF0RMg5