| Name | Company Number | Date Appointed | Rating |
|---|
| Name | Company Number | Date Appointed | Date Resigned | Rating |
|---|---|---|---|---|
| B N F L Engineering Ltd | 02493959 | 23/08/1994 | 31/10/2001 | Dissolved |
| BIL SOLUTIONS LIMITED | 02888907 | 02/10/1996 | 30/01/1998 | Dissolved |
| BRITISH NUCLEAR GROUP LIMITED | 05245506 | 30/06/2008 | 01/11/2008 | Silver |
| Bnes Ltd. | 03333868 | 07/07/1997 | 06/07/2000 | Dissolved |
| DEFENCE CONTRACTOR MANAGEMENT AND OPERATIONS LIMITED | 03664571 | 01/10/2007 | 07/05/2009 | Not Trading |
| GREAT BRITISH NUCLEAR | 05027024 | 17/03/2005 | 01/11/2008 | Silver |
| I.T. Services Ltd | 02953839 | 24/02/1995 | 01/10/1996 | Dissolved |
| INTERNATIONAL NUCLEAR SERVICES LIMITED | 01144352 | 06/12/1991 | 01/10/1995 | Silver |
| Intermox Limited | 02371981 | 30/09/1992 | 01/10/1994 | Dissolved |
| International Energy Systems Ltd | 02823699 | 06/04/1995 | 01/10/1996 | Dissolved |
| NATIONAL SKILLS ACADEMY FOR NUCLEAR LIMITED | 06423637 | 23/01/2008 | 31/03/2011 | Gold |
| NDA PROPERTIES LIMITED | 02970356 | 16/01/1995 | 13/03/2002 | Silver |
| NUCLEAR RESTORATION SERVICES LIMITED | 02264251 | 19/11/2004 | 01/07/2006 | Amber |
| PACIFIC NUCLEAR TRANSPORT LIMITED | 01228109 | 18/12/2003 | 11/12/2006 | Bronze |
| SELLAFIELD LIMITED | 01002607 | 29/11/2007 | 24/11/2008 | Silver |
| United Kingdom Nirex Ltd | 01927761 | 22/09/1997 | 06/12/2001 | Dissolved |