| Name | Company Number | Date Appointed | Rating |
|---|---|---|---|
| CHASE NETWORK LIMITED | 02914110 | 08/04/1994 | Dissolved |
| Ingressus Ltd | 06208915 | 11/04/2007 | Dissolved |
| SIMS RAIL LIMITED | 09305739 | 11/11/2014 | Dissolved |
| Signalling Control Services Ltd | 03738427 | 22/04/1999 | Dissolved |
| Signalling Design Services Ltd | 03738176 | 22/04/1999 | Dissolved |
| Signalling Support Services Ltd | 03680391 | 08/12/1998 | Dissolved |
| Signalling Support Services Ltd | 03680391 | 08/12/1998 | Dissolved |
| Vectura Holdings Plc | 03747603 | 22/04/1999 | Dissolved |
| Vital Force Remedies Ltd | 03684590 | 21/12/1998 | Dissolved |
| Name | Company Number | Date Appointed | Date Resigned | Rating |
|---|---|---|---|---|
| METRO PROJECT SERVICES LIMITED | 03277254 | 12/11/1996 | 01/08/1997 | Dissolved |
| SIGNALLING INSTALLATION & MAINTENANCE SERVICES LIMITED | 02953526 | 28/07/1994 | 31/08/2019 | Silver |