| Anglian Water Services Limited | Anglian House, Ambury Road, Huntingdon, Cambs. PE18 6NZ |
| Bournemouth and West Hampshire PLC | George Jessel House, Francis Avenue, Bournemouth, Dorset BH11 8NB |
| Bristol Water plc | PO Box 218, Bridgwater Road, Bristol BS99 7AU |
| Cambridge Water Company | 41 Rustat Road, Cambridge CB1 3QS |
| Cholderton and District Water Company Limited | Estate Office, Cholderton, Salisbury, Wilts. SP4 0DR |
| Essex and Suffolk Water plc | Hall Street, Chelmsford, Essex CM2 0HH |
| Folkestone and Dover Water Services Limited | Cherry Garden Lane, Folkestone, Kent CT19 4QB |
| Hartlepool Water plc | 3 Lancaster Road, Hartlepool TS24 8LW |
| Mid Kent Water plc | PO Box 45, Snodland, Kent ME6 5AH |
| Mid Southern Water Plc | Frimley Green, Camberley, Surrey GU16 6HZ |
| North Surrey Water Ltd | Millis House, The Causeway, Staines, Middlesex TW18 3BX |
| North West Water Ltd | Lingley Mere, Warrington, Lancs WA5 3LP |
| Northumbrian Water Limited | Abbey Road, Pity Me, Durham DH1 5FJ |
| Portsmouth Water plc | PO Box 8, West Street, Havant, Hants PO9 1LG |
| Severn Trent Water Limited | 2297 Coventry Road, Birmingham B26 3PU |
| South East Water PLC | 3 Church Road, Haywards Heath, West Sussex RH16 3LP |
| South Staffordshire Water plc | Green Lane, Walsall, West Midlands WS2 7PD |
| South West Water Services Ltd | Peninsula House, Rydon Lane, Exeter EX2 7HR |
| Southern Water Services Ltd | Southern House, Yeoman Road, Worthing, West Sussex BN13 3NX |
| Sutton and East Surrey Water plc | London Road, Redhill, Surrey RH1 1LJ |
| Tendring Hundred Water Services Ltd | Mill Hill, Manningtree, Essex CO11 2AZ |
| Thames Water Utilities Ltd | Gainsborough House, Manor Farm Road, Reading RG2 0JN |
| Three Valleys Water plc | PO Box 48, Bishops Rise, Hatfield, Herts AL10 9HL |
| Wessex Water Services Limited | Wessex House, Passage Street, Bristol BS2 0JQ |
| York Waterworks plc | Lendal Tower, York YO1 7DL |
| Yorkshire Water Services Ltd | Western House, Western Way, Bradford BD6 2LZ |