| Name | Company Number | Date Appointed | Rating |
|---|---|---|---|
| ELECTRICITY ASSOCIATION SERVICES LIMITED | 02366837 | 16/10/2003 | Dissolved |
| WPD 1957 LIMITED | 04240852 | 17/01/2003 | Dissolved |
| Name | Company Number | Date Appointed | Date Resigned | Rating |
|---|---|---|---|---|
| ENERGY NETWORKS ASSOCIATION LIMITED | 04832301 | 21/10/2016 | 07/11/2018 | One Red Flag |
| METER READING SERVICES LIMITED | 02578780 | 23/10/1997 | 31/07/2017 | Dissolved |
| NATIONAL GRID ELECTRICITY DISTRIBUTION (EAST MIDLANDS) PLC | 02366923 | 01/04/2011 | 07/11/2018 | Silver |
| NATIONAL GRID ELECTRICITY DISTRIBUTION (SOUTH WALES) PLC | 02366985 | 15/09/2000 | 07/11/2018 | Bronze |
| NATIONAL GRID ELECTRICITY DISTRIBUTION (SOUTH WEST) PLC | 02366894 | 23/10/1997 | 07/11/2018 | Silver |
| NATIONAL GRID ELECTRICITY DISTRIBUTION (WEST MIDLANDS) PLC | 03600574 | 01/04/2011 | 07/11/2018 | Silver |
| NATIONAL GRID ELECTRICITY DISTRIBUTION INVESTMENTS LIMITED | 02202625 | 07/03/2001 | 31/07/2017 | Silver |
| NATIONAL GRID ELECTRICITY DISTRIBUTION MIDLANDS LIMITED | 02366928 | 29/03/2011 | 31/07/2017 | Gold |
| NATIONAL GRID ELECTRICITY DISTRIBUTION NETWORK HOLDINGS LIMITED | 08857746 | 24/01/2014 | 07/11/2018 | Silver |
| NATIONAL GRID ELECTRICITY DISTRIBUTION PLC | 09223384 | 16/10/2014 | 07/11/2018 | Bronze |
| PPL UK DISTRIBUTION HOLDINGS LIMITED | 04267536 | 21/12/2001 | 31/07/2017 | Dissolved |
| PPL UK RESOURCES LIMITED | 04506336 | 19/02/2003 | 31/07/2017 | Silver |
| WPD MIDLANDS NETWORKS CONTRACTING LIMITED | 02710658 | 01/04/2011 | 31/07/2017 | Dissolved |
| WPD MIDLANDS PROPERTIES LIMITED | 03600545 | 01/04/2011 | 31/07/2017 | Dissolved |
| WPD WEM HOLDINGS LIMITED | 07578676 | 25/03/2011 | 31/07/2017 | Silver |
| WPD WEM LIMITED | 04066211 | 19/12/2000 | 31/07/2017 | Silver |