| Name | Company Number | Date Appointed | Rating |
|---|---|---|---|
| Bentley Holdings Ltd | 02789058 | 11/02/1994 | Dissolved |
| DORMHEAD LIMITED | 01953932 | 21/09/1991 | Dissolved |
| Dorsetden Limited | 02017566 | 31/07/1991 | Dissolved |
| Ingleby (413) Ltd | 02393867 | 09/06/1991 | Dissolved |
| Ingleby (417) Ltd | 02393802 | 09/06/1991 | Dissolved |
| Regal Industrial Holdings Ltd | 02431582 | 01/03/1993 | Dissolved |
| Name | Company Number | Date Appointed | Date Resigned | Rating |
|---|---|---|---|---|
| Bentley Trustees Ltd | 02369042 | 04/12/1991 | 01/09/1993 | Dissolved |
| CAMBRIDGE CORRELATORS LIMITED | 04075546 | 21/09/2000 | 21/07/2005 | Dissolved |
| CAMBRIDGE PHOTONICS LIMITED | 04078372 | 26/09/2000 | 14/11/2018 | Not Trading |
| CRANE ELECTRONICS GROUP LIMITED | 04027994 | 18/12/2000 | 29/11/2001 | Bronze |
| CRANE ELECTRONICS LIMITED | 01029811 | 30/08/1992 | 29/11/2001 | Silver |
| FERGUSON INTERNATIONAL PLC | 00197499 | 03/08/1991 | 06/07/1995 | Dissolved |
| LGC (JAPAN) LIMITED | 02754784 | 01/11/1999 | 14/03/2003 | Gold |
| PARALLEL PHOTONIC SYSTEMS LIMITED | 03133979 | 07/08/2000 | 14/11/2018 | Gold |
| THOMAS SWAN & CO.LIMITED | 00210794 | 01/01/1997 | 14/11/2018 | Silver |
| THOMAS SWAN HOLDINGS LIMITED | 09777330 | 23/09/2015 | 14/11/2018 | Silver |