| Name | Company Number | Date Appointed | Rating |
|---|---|---|---|
| NNB GENERATION COMPANY (HPC) LIMITED | 06937084 | 21/09/2017 | Amber |
| NNB HOLDING COMPANY (HPC) LIMITED | 06937080 | 01/01/2014 | Bronze |
| NNB TOP COMPANY HPC (A) LTD | 09284749 | 01/11/2017 | Bronze |
| NNB TOP COMPANY HPC (B) LTD | 09284753 | 01/11/2017 | Bronze |
| SIZEWELL C LIMITED | 09284825 | 15/11/2017 | Silver |
| Name | Company Number | Date Appointed | Date Resigned | Rating |
|---|---|---|---|---|
| EDF ENERGY (COTTAM POWER) LIMITED | 04074196 | 01/01/2014 | 01/07/2014 | Dissolved |
| EDF ENERGY (ENERGY BRANCH) LIMITED | 02449611 | 01/01/2014 | 31/10/2017 | Dissolved |
| EDF ENERGY (THERMAL GENERATION) LIMITED | 04267569 | 01/01/2014 | 01/07/2014 | Gold |
| EDF ENERGY R&D UK CENTRE LIMITED | 02948613 | 23/03/2012 | 01/10/2014 | Gold |
| EDF ENERGY ROUND 3 ISLE OF WIGHT LIMITED | 04600558 | 01/01/2014 | 01/07/2014 | Dissolved |