| Name | Company Number | Date Appointed | Rating |
|---|---|---|---|
| Southern Gas Ltd | 02661127 | 29/07/2002 | Dissolved |
| Name | Company Number | Date Appointed | Date Resigned | Rating |
|---|---|---|---|---|
| EASTERN POWER NETWORKS PLC | 02366906 | 07/02/2002 | 29/10/2010 | Bronze |
| EDF ENERGY (DORMANT HOLDINGS) LIMITED | 04431799 | 04/07/2002 | 17/02/2012 | Dissolved |
| EDF ENERGY (ENERGY BRANCH) LIMITED | 02449611 | 07/02/2002 | 17/02/2012 | Dissolved |
| EDF ENERGY (UK) LIMITED | 02622406 | 30/08/2000 | 31/10/2017 | Amber |
| EDF ENERGY CUSTOMERS LIMITED | 02228297 | 07/02/2002 | 17/02/2012 | Silver |
| EDF ENERGY GROUP HOLDINGS LIMITED | 03261188 | 07/02/2002 | 31/10/2017 | Dissolved |
| EDF ENERGY HOLDINGS LIMITED | 06930266 | 10/06/2009 | 31/10/2017 | Bronze |
| EDF ENERGY INVESTMENTS | 03123865 | 29/07/2002 | 17/02/2012 | Dissolved |
| EDF ENERGY LAKE LIMITED | 09200461 | 24/11/2014 | 31/10/2017 | Silver |
| EDF ENERGY LIMITED | 02366852 | 07/02/2002 | 31/10/2017 | Silver |
| EDF ENERGY RENEWABLES HOLDINGS LIMITED | 06658187 | 28/07/2008 | 24/04/2012 | Silver |
| LAKE ACQUISITIONS LIMITED | 06612465 | 05/06/2008 | 31/10/2017 | Silver |
| LONDON POWER NETWORKS PLC | 03929195 | 07/02/2002 | 29/10/2010 | Silver |
| NNB HOLDING COMPANY (BRB) LTD | 09284746 | 17/11/2014 | 31/10/2017 | Dissolved |
| NNB HOLDING COMPANY (HPC) LIMITED | 06937080 | 17/06/2009 | 31/10/2017 | Bronze |
| NNB TOP COMPANY HPC (A) LTD | 09284749 | 17/11/2014 | 31/10/2017 | Bronze |
| NNB TOP COMPANY HPC (B) LTD | 09284753 | 17/11/2014 | 31/10/2017 | Bronze |
| SEEBOARD INTERNATIONAL LIMITED | 02693107 | 29/07/2002 | 17/02/2012 | Dissolved |
| SIZEWELL C (HOLDING) LIMITED | 09284751 | 17/11/2014 | 31/10/2017 | Silver |
| SOUTH EASTERN POWER NETWORKS PLC | 03043097 | 29/07/2002 | 29/10/2010 | Silver |
| UK POWER NETWORKS (OPERATIONS) LIMITED | 03870728 | 07/02/2002 | 29/10/2010 | Bronze |
| UK POWER NETWORKS SERVICES (ASSET MANAGEMENT) LIMITED | 03003570 | 29/07/2002 | 29/10/2010 | Gold |