| Name | Company Number | Date Appointed | Rating |
|---|---|---|---|
| GLENTWORTH RAIL LIMITED | 05324577 | 12/03/2018 | Dissolved |
| WILLIAM COOK (MS) 2018 LIMITED | 00053475 | 23/03/2018 | Dissolved |
| WILLIAM COOK INTEGRITY LIMITED | 02070684 | 02/07/2021 | Dissolved |
| WILLIAM COOK MASTER PATTERNS LIMITED | 02610170 | 10/06/2020 | Dissolved |
| WILLIAM COOK NDT LIMITED | 01011570 | 13/05/2020 | Dissolved |
| WILLIAM COOK PRECISION LIMITED | 00533243 | 13/05/2020 | Dissolved |
| Name | Company Number | Date Appointed | Date Resigned | Rating |
|---|---|---|---|---|
| ASTRUM (UK) LIMITED | 07377029 | 03/04/2017 | 24/04/2024 | Not Trading |
| CHESTERFIELD METAL TECHNOLOGIES LIMITED | 12403434 | 16/01/2020 | 24/04/2024 | Bronze |
| COOK RAIL SYSTEMS LIMITED | 09795392 | 09/06/2021 | 12/07/2024 | Not Trading |
| WEARDALE INVESTMENTS LIMITED | 12403512 | 16/01/2020 | 24/04/2024 | Not Trading |
| WILLIAM COOK AVIATION LIMITED | 05922668 | 13/03/2009 | 24/04/2024 | One Red Flag |
| WILLIAM COOK CAST PRODUCTS LIMITED | 02727560 | 23/03/2018 | 24/04/2024 | Bronze |
| WILLIAM COOK DEFENCE LIMITED | 07810738 | 03/04/2017 | 24/04/2024 | Not Trading |
| WILLIAM COOK ESTATES LIMITED | 02311818 | 31/10/2008 | 24/04/2024 | Amber |
| WILLIAM COOK INTERMODAL LIMITED | 01483687 | 28/03/2018 | 24/04/2024 | Amber |
| WILLIAM COOK LEASEHOLDS LIMITED | 07377847 | 03/04/2017 | 24/04/2024 | One Red Flag |
| WILLIAM COOK LEEDS LIMITED | 02727561 | 23/03/2018 | 24/04/2024 | One Red Flag |
| WILLIAM COOK LIMITED | 00074837 | 03/04/2017 | 24/04/2024 | Not Trading |
| WILLIAM COOK PROPERTIES LIMITED | 02362462 | 31/10/2008 | 24/04/2024 | Bronze |
| WILLIAM COOK PUBLISHING LIMITED | 07377064 | 03/04/2017 | 24/04/2024 | Gold |
| WILLIAM COOK RAIL LIMITED | 08694277 | 28/03/2018 | 24/04/2024 | Bronze |
| WILLIAM COOK STANHOPE LIMITED | 00359586 | 28/03/2018 | 24/04/2024 | Bronze |