| Name | Company Number | Date Appointed | Rating |
|---|---|---|---|
| CALDER FINCO UK LTD | 05721362 | 01/09/2020 | Gold |
| CALDER GROUP HOLDINGS LIMITED | 09457820 | 01/09/2020 | Silver |
| CALDER GROUP LIMITED | 03491249 | 01/09/2020 | Amber |
| CALDER HOLDINGS LIMITED | 03491252 | 01/09/2020 | One Red Flag |
| CALDER INDUSTRIAL MATERIALS LIMITED | 00028073 | 01/09/2020 | Bronze |
| CALDER INTERNATIONAL HOLDINGS LIMITED | 03491092 | 01/09/2020 | Gold |
| LEEDS BRONZE ENGINEERING LIMITED | 03491043 | 23/10/2023 | Amber |
| STAMPTREE LIMITED | 05636469 | 01/09/2020 | Silver |
| Name | Company Number | Date Appointed | Date Resigned | Rating |
|---|---|---|---|---|
| AMEC NUCLEAR M & O LIMITED | 05664844 | 31/01/2007 | 05/02/2007 | Dissolved |
| AMEC NUCLEAR PROJECTS LIMITED | 05664962 | 31/01/2007 | 05/02/2007 | Dissolved |
| AMERCARE LIMITED | 02350378 | 21/11/1995 | 18/12/1997 | Gold |
| I.T. Services Ltd | 02953839 | 22/10/1996 | 27/01/1998 | Dissolved |
| NATIONAL SKILLS ACADEMY FOR NUCLEAR LIMITED | 06423637 | 26/03/2009 | 07/02/2013 | Gold |
| NUCLEAR MANAGEMENT PARTNERS LIMITED | 05894268 | 25/03/2008 | 23/01/2013 | Dissolved |
| SPRINGFIELDS FUELS LIMITED | 03857770 | 01/04/2005 | 26/09/2006 | Gold |
| THE LANCASHIRE PARTNERSHIP AGAINST CRIME LIMITED | 03328436 | 06/03/2002 | 21/07/2004 | Amber |
| TSB (INVESTMENT EUROPE) LIMITED | 03976730 | 14/04/2000 | 26/07/2006 | Dissolved |
| URANIUM ASSET MANAGEMENT LIMITED | 03162046 | 07/02/2000 | 26/09/2006 | Gold |
| WESTINGHOUSE ELECTRIC COMPANY UK LIMITED | 04006213 | 26/05/2000 | 01/01/2004 | Silver |
| WESTINGHOUSE ELECTRIC ENERGY SYSTEMS UK LIMITED | 03108756 | 31/08/2000 | 18/11/2003 | Dissolved |
| WESTINGHOUSE ELECTRIC UK HOLDINGS LIMITED | 02458109 | 01/04/2005 | 26/09/2006 | Bronze |
| WOOD FINANCE UK LIMITED | 03725076 | 31/01/2007 | 01/03/2013 | Gold |