| Name | Company Number | Date Appointed | Rating |
|---|---|---|---|
| CHESHIRE CAVITY STORAGE 1 LIMITED | 06438979 | 01/04/2023 | Silver |
| EDF ENERGY (THERMAL GENERATION) LIMITED | 04267569 | 01/04/2023 | Gold |
| EDF ENERGY (TSO) LIMITED | 03432165 | 05/01/2024 | Bronze |
| EDF ENERGY INNOVATION LIMITED | 06999483 | 01/04/2023 | Dissolved |
| EDF ENERGY R&D UK CENTRE LIMITED | 02948613 | 01/08/2024 | Silver |
| NUCLEAR SERVICES (TECHNICAL) COMPANY LIMITED | 15749828 | 30/05/2024 | Amber |
| WEST BURTON PROPERTY LIMITED | 04267566 | 01/04/2023 | Not Trading |
| Name | Company Number | Date Appointed | Date Resigned | Rating |
|---|---|---|---|---|
| KISTOS ENERGY STORAGE LIMITED | 02850057 | 01/04/2023 | 23/04/2024 | One Red Flag |
| NNB GENERATION COMPANY (HPC) LIMITED | 06937084 | 06/06/2018 | 01/12/2022 | Amber |
| SIZEWELL C LIMITED | 09284825 | 01/12/2022 | 03/04/2023 | Silver |