| Name | Company Number | Date Appointed | Rating |
|---|---|---|---|
| WALES & WEST GAS NETWORKS (HOLDINGS) LIMITED | 05095454 | 18/07/2013 | Silver |
| WALES & WEST GAS NETWORKS (JUNIOR FINANCE) LIMITED | 05149491 | 18/07/2013 | Dissolved |
| WALES & WEST GAS NETWORKS (SENIOR FINANCE) LIMITED | 05149493 | 18/07/2013 | Dissolved |
| WALES & WEST UTILITIES FINANCE PLC | 06766848 | 18/07/2013 | Silver |
| WALES & WEST UTILITIES HOLDINGS LIMITED | 07092596 | 18/07/2013 | Silver |
| WALES & WEST UTILITIES LIMITED | 05046791 | 10/06/2013 | Silver |
| WEST & WESTERN MIDCO FINANCE PLC | 15124716 | 08/09/2023 | Silver |
| WEST GAS NETWORKS LIMITED | 08151511 | 18/07/2013 | Silver |
| WESTERN GAS NETWORKS LIMITED | 08151473 | 18/07/2013 | Silver |
| Name | Company Number | Date Appointed | Date Resigned | Rating |
|---|---|---|---|---|
| ENETT INTERNATIONAL (UK) LIMITED | 02509464 | 01/10/2003 | 10/06/2005 | One Red Flag |
| GALILEO PORTUGAL LIMITED | 03008824 | 01/10/2003 | 10/06/2005 | Amber |
| THE GALILEO COMPANY | 02143570 | 01/10/2003 | 10/06/2005 | Amber |
| TRAVELPORT UNITED KINGDOM LIMITED | 03793684 | 01/10/2003 | 10/06/2005 | Dissolved |
| WALES & WEST UTILITIES PENSION SCHEME TRUSTEES LIMITED | 05750643 | 15/11/2006 | 10/02/2011 | Not Trading |
| XOSERVE LIMITED | 05046877 | 01/06/2014 | 01/04/2017 | Silver |