| Tearfund | www.tearfund.org |
| Thames 21 | www.thames21.org.uk |
| Thames Water Utilities Ltd | www.thameswater.co.uk |
| Tourism Concern | www.tourismconcern.org.uk |
| Tourism Management Institute (TMI) | www.tmi.org.uk |
| Tourism Society | www.tourismsociety.org |
| Town & Country Planning Association | www.tcpa.org.uk |
| UK Atomic Energy Authority (UKAEA) | www.ukaea.org.uk |
| UK Centre for Economic and Environmental Development (UKCEED) | www.ukceed.org |
| UK Energy Saving | www.uk-energy-saving.com |
| UK Environmental Law Association (UKELA) | www.ukela.org |
| UK Water Industry Research (UKWIR) | www.ukwir.org |
| Union Fenosa | www.uef.es |
| UNISON | www.unison.org.uk |
| United Kingdom Society for Trenchless Technology (UKSTT) | www.ukstt.org.uk |
| United Nations Educational Scientific and Cultural Organization (UNESCO) Water Portal | www.unesco.org/water |
| United Utilities Water plc | www.unitedutilities.com |
| Veolia Water East
(formerly Tendring Hundred Water) |
www.veoliawater.co.uk |
| Veolia Water Southeast (formerly Folkestone and Dover Water) | www.veoliawater.co.uk |
| Veolia Water Three Valleys
(formerly Three Valleys Water) |
www.veoliawater.co.uk |
