Liquidity Extension Update

Thames Water Utilities Finance plc

15 August 2025

Liquidity Extension Update - Transaction Effective Date

Thames Water Utilities Limited ("TWUL") announced the launch of a liquidity extension transaction on 25 October 2024 (the "Liquidity Extension Transaction"). This announcement can be found here:

https://www.londonstockexchange.com/news-article/AW14/liquidity-extension-update/16731710

Thames Water Utilities Finance plc hereby announces that TWUL has made an update announcement in respect of the Liquidity Extension Transaction:

https://www.londonstockexchange.com/news-article/AW14/liquidity-extension-update/17185652

For further information

Investor enquiries

Frederick Maroudas - Director of Corporate Finance debt.investorrelations@thameswater.co.uk

Media enquiries

Suvra Jans - Head of Media Relations suvra.jans@thameswater.co.uk M: 07747 640 810

Alex Simmons thameswater@edelmansmithfield.com  M: 07970 174 353