| Name | Company Number | Date Appointed | Rating |
|---|---|---|---|
| ACETIP | 01576464 | 31/05/2016 | Dissolved |
| ALBION WATER (SHOTTON) LIMITED | 03695161 | 31/03/2014 | Dissolved |
| ANALAQ LIMITED | 02114891 | 31/05/2016 | Dissolved |
| BOURNEMOUTH WATER INVESTMENTS LIMITED | 05321147 | 15/12/2022 | Dissolved |
| BOURNEMOUTH WATER LIMITED | 02924312 | 15/12/2022 | Dissolved |
| BWH ENTERPRISES LIMITED | 03764413 | 15/12/2022 | Dissolved |
| CAMBRIDGE WATER BUSINESS LIMITED | 09911986 | 08/07/2020 | Dissolved |
| CENTRE FOR ENVIRONMENTAL RESEARCH LIMITED | 03367354 | 31/03/2014 | Dissolved |
| D.M.P. (HOLDINGS) LIMITED | 02094479 | 31/05/2016 | Dissolved |
| ELE DATASYSTEMS | 01085369 | 31/05/2016 | Dissolved |
| GREENHILL ENVIRONMENTAL LIMITED | 01772778 | 31/05/2016 | Dissolved |
| HAUL WASTE LIMITED | 00679090 | 31/05/2016 | Dissolved |
| PENINSULA | 00685236 | 31/05/2016 | Dissolved |
| PENINSULA LEASING LIMITED | 03926798 | 31/05/2016 | Dissolved |
| PENINSULA WATER LIMITED | 02592778 | 31/03/2014 | Dissolved |
| PENNON SOUTH WEST LIMITED | 02421516 | 31/05/2016 | Dissolved |
| PENNON WASTE MANAGEMENT LIMITED | 00574299 | 31/05/2016 | Dissolved |
| PHOX SYSTEMS LIMITED | 01081019 | 31/05/2016 | Dissolved |
| RYDON PROPERTIES LIMITED | 02406261 | 31/05/2016 | Dissolved |
| SEAL SECURITY SYSTEMS LIMITED | 01841937 | 31/05/2016 | Dissolved |
| SOUTH STAFFORDSHIRE WATER BUSINESS LIMITED | 09847311 | 08/07/2020 | Dissolved |
| SSWB LIMITED | 09911716 | 08/07/2020 | Dissolved |
| THE METROPOLITAN WATER COMPANY LIMITED | 03376014 | 31/03/2014 | Dissolved |
| VIRIDOR CONTRACTING LIMITED | 03736621 | 31/05/2016 | Dissolved |
| VIRIDOR ENTERPRISES LIMITED | 02089280 | 31/05/2016 | Dissolved |
| VIRIDOR SOUTH WEST LIMITED | 02649478 | 31/05/2016 | Dissolved |
| WATER WEST LIMITED | 01195844 | 31/05/2016 | Dissolved |
| Name | Company Number | Date Appointed | Date Resigned | Rating |
|---|---|---|---|---|
| AVON VALLEY WATER LIMITED | 06691170 | 15/12/2022 | 31/12/2023 | Not Trading |
| BRISTOL WATER CORE HOLDINGS LIMITED | 04637554 | 03/06/2021 | 31/12/2023 | Silver |
| BRISTOL WATER HOLDINGS LIMITED | 02630760 | 03/06/2021 | 31/12/2023 | Bronze |
| BRISTOL WATER HOLDINGS UK LIMITED | 04789566 | 03/06/2021 | 31/12/2023 | Bronze |
| BRISTOL WATER PLC | 02662226 | 03/06/2021 | 31/12/2023 | Amber |
| DUNFERMLINE SOLAR LIMITED | 12683727 | 07/06/2023 | 31/12/2023 | One Red Flag |
| EEB16 LIMITED | 10789260 | 10/07/2023 | 31/12/2023 | One Red Flag |
| EXE CONTINENTAL | 02376963 | 31/05/2016 | 11/04/2023 | Dissolved |
| PENINSULA PROPERTIES (EXETER) LIMITED | 02307220 | 09/12/2020 | 31/12/2023 | Silver |
| PENINSULA TRUSTEES LIMITED | 02476685 | 03/11/2015 | 31/12/2023 | Not Trading |
| PENNON GROUP PLC | 02366640 | 08/07/2020 | 31/12/2023 | Silver |
| PENNON LIMITED | 02456469 | 26/01/2023 | 31/12/2023 | Not Trading |
| PENNON PENSION TRUSTEES LIMITED | 02388620 | 25/03/2015 | 31/12/2023 | Not Trading |
| PENNON POWER LIMITED | 00736732 | 31/05/2016 | 31/12/2023 | Silver |
| PENNON SHARE SCHEMES TRUSTEES LIMITED | 02388662 | 22/11/2022 | 31/12/2023 | Dissolved |
| PENNON TRUSTEE LIMITED | 02456467 | 22/11/2022 | 31/12/2023 | Dissolved |
| PENNON WATER SERVICES LIMITED | 09902835 | 08/07/2020 | 31/12/2023 | Silver |
| SOUTH WEST WATER CUSTOMER SERVICES LIMITED | 07620338 | 15/12/2022 | 31/12/2023 | Amber |
| SOUTH WEST WATER FINANCE PLC | 05722435 | 31/05/2016 | 31/12/2023 | Silver |
| SOUTH WEST WATER LIMITED | 02366665 | 01/09/2022 | 31/12/2023 | Bronze |
| SOUTH WEST WATER SERVICES LIMITED | 03559566 | 26/01/2023 | 31/12/2023 | Not Trading |
| SWW PENSION TRUSTEES LIMITED | 02451999 | 31/05/2016 | 31/12/2023 | Not Trading |
| VIRIDOR WASTE 2 LIMITED | 02298543 | 31/05/2016 | 31/12/2023 | Silver |