| Name | Company Number | Date Appointed | Rating |
|---|---|---|---|
| CAMBRIAN UTILITIES LIMITED | 10082803 | 19/11/2019 | One Red Flag |
| DWR CYMRU (FINANCING) UK PLC | 11949988 | 01/01/2020 | Silver |
| DWR CYMRU (HOLDINGS) LIMITED | 03954867 | 01/01/2020 | Silver |
| DWR CYMRU CYFYNGEDIG | 02366777 | 01/01/2020 | Amber |
| GLAS CYMRU (SECURITIES) CYFYNGEDIG | 04129132 | 01/01/2020 | Amber |
| GLAS CYMRU ANGHYFYNGEDIG | 03975719 | 01/01/2020 | Bronze |
| GLAS CYMRU HOLDINGS CYFYNGEDIG | 09917809 | 01/01/2020 | Bronze |
| HYDRO 1 LIMITED | 09325458 | 28/01/2015 | Dissolved |
| WALES & WEST UTILITIES FINANCE PLC | 06766848 | 01/04/2023 | Silver |
| WALES & WEST UTILITIES LIMITED | 05046791 | 01/04/2023 | Silver |
| WELSH WATER HOLDINGS LIMITED | 10079953 | 19/11/2019 | One Red Flag |
| WELSH WATER INFRASTRUCTURE LIMITED | 10082776 | 19/11/2019 | One Red Flag |
| WELSH WATER ORGANIC ENERGY (CARDIFF) LTD | 08356859 | 19/11/2019 | Amber |
| WELSH WATER ORGANIC ENERGY LTD | 08356949 | 19/11/2019 | Bronze |
| WELSH WATER ORGANIC WASTE LIMITED | 11468450 | 19/11/2019 | Silver |
| YSTRADGYNLAIS PROPERTIES LIMITED | 06217620 | 05/06/2007 | Not Trading |
| YSTRADGYNLAIS PROPERTIES LIMITED | 06217620 | 05/06/2007 | Not Trading |
| Name | Company Number | Date Appointed | Date Resigned | Rating |
|---|---|---|---|---|
| 1ST Line Digital.Com Ltd | 03461818 | 14/03/2000 | 29/05/2000 | Dissolved |
| 1ST Line Insurance Services Plc | 03351215 | 14/03/2000 | 29/05/2000 | Dissolved |
| 1ST Line Mobile Communications Plc | 03665364 | 14/03/2000 | 29/05/2000 | Dissolved |
| WELSH WATER PENSION TRUSTEE LIMITED | 04328831 | 26/11/2001 | 01/10/2021 | Not Trading |