Scrip Dividend Reference Price

The Company announces that the Scrip Dividend Reference Price for the fully paid shares in the Company to be issued to shareholders who elect to receive the scrip dividend alternative for the interim dividend for the year ending 31 December 2026 is 253.4 pence per ordinary share of 1 pence each.

The Scrip Dividend Reference Price has been calculated as the average value of the middle market closing price for the Company's ordinary shares as derived from the Daily Official List of the London Stock Exchange for the five consecutive dealing days commencing on the ex-dividend date. The Company's ordinary shares were marked ex-dividend on 17 September 2026.

Shareholders wishing to receive the scrip dividend in respect of the interim dividend for the year ending 31 December 2026 and who have not already submitted a mandate form should return a mandate form to the Registrar, Equiniti, Share Dividend Team, Aspect House, Spencer Road, Lancing, West Sussex, BN99 6DA by 2 October 2026.

For more information regarding the scrip dividend including the terms, and to download the mandate form, see Costain scrip.

If you have already completed a valid scrip dividend mandate form, it will remain valid until you cancel your election and you need not return any further documentation to receive this scrip dividend.

The interim dividend for the year ending 31 December 2026, including the scrip dividend, will be paid on 23 October 2026 (the dividend payment date), to the ordinary shareholders of the Company on the register at close of business on 18 September 2026 (the record date).

For further information, please contact Equiniti on +44 (0)371 384 2268*.

* Please use the country code when calling from outside the UK. Lines are open from 08:30 to 17:30 (UK time), Monday to Friday (excluding public holidays in England and Wales).