| Name | Company Number | Date Appointed | Rating |
|---|---|---|---|
| INTELLIGENT TOYS LIMITED | 04173210 | 20/07/2001 | Dissolved |
| Mensa at Cambridge Ltd | 01541008 | 31/12/1991 | Dissolved |
| Sinclair Equipment International Ltd | 00780353 | 19/07/1991 | Dissolved |
| Sinclair Research U K Ltd | 01420583 | 19/07/1991 | Dissolved |
| X Bike Co Ltd (The) | SC128464 | 14/11/1990 | Dissolved |
| Name | Company Number | Date Appointed | Date Resigned | Rating |
|---|---|---|---|---|
| Anamartic Ltd | 02003143 | 07/09/1991 | 07/04/1994 | Dissolved |
| BRITISH MENSA LIMITED | 00971663 | 30/09/1991 | 18/10/1997 | Amber |
| Daka Research (Uk) Ltd | 04467456 | 21/06/2002 | 10/07/2006 | Dissolved |
| MENSA INTERNATIONAL LIMITED | 00848100 | 24/01/1992 | 04/02/1998 | Gold |
| SINCLAIR DIRECT LIMITED | 02837198 | 19/07/1993 | 15/05/1994 | Dissolved |
| SINCLAIR RESEARCH LIMITED | 01135105 | 09/07/1992 | 16/09/2021 | Not Trading |
| Symbolkit Ltd | 02108798 | 19/07/1991 | 07/10/1995 | Dissolved |
| The Exploratory | 01717236 | 31/12/1992 | 25/03/1993 | Dissolved |
| YORK CENTRAL RESIDENTS' ASSOCIATION LIMITED | 03617350 | 18/08/1998 | 30/11/2000 | Gold |