| Name | Company Number | Date Appointed | Rating |
|---|---|---|---|
| BRITISH TRUST FOR ORNITHOLOGY(THE) | 00357284 | 01/01/2020 | Bronze |
| C COMMUNICATIONS LIMITED | 04381130 | 26/01/2007 | Dissolved |
| C EVENTS LIMITED | 05272838 | 26/01/2007 | Dissolved |
| C SQUARED HOLDINGS LIMITED | 05272863 | 26/01/2007 | Dissolved |
| C SQUARED PARTNERSHIPS LIMITED | 05272869 | 26/01/2007 | Dissolved |
| ENTER OPERATING SYSTEMS LIMITED | 10157975 | 30/04/2016 | Dissolved |
| HSR MANAGEMENT LIMITED | 02398245 | 24/06/1993 | Dissolved |
| HSR MANAGEMENT LIMITED | 02398245 | 14/12/2004 | Dissolved |
| PACKET VISION LIMITED | 05114469 | 01/07/2006 | Dissolved |
| Name | Company Number | Date Appointed | Date Resigned | Rating |
|---|---|---|---|---|
| C B C L Ltd | 00332963 | 31/10/1991 | 31/05/1992 | Dissolved |
| CONSOLIDATED PR LIMITED | 04185824 | 01/03/2003 | 01/05/2005 | Amber |
| Cornwall Local Radio Ltd | 04584672 | 03/10/2003 | 01/11/2005 | Dissolved |
| D&AD | 00883234 | 28/01/2004 | 14/09/2006 | Silver |
| D&AD TRADING LIMITED | 05313369 | 15/12/2004 | 14/09/2006 | Silver |
| ETV REALISATIONS (2021) LIMITED | 05250283 | 16/12/2004 | 09/08/2011 | Dissolved |
| Equinox Communications Ltd | 00980058 | 16/03/1998 | 31/05/2005 | Dissolved |
| Haymarket Marketing Publications Ltd | 01810242 | 12/04/1995 | 13/03/1998 | Dissolved |
| ISLES OF SCILLY STEAMSHIP COMPANY LIMITED | 00165746 | 16/05/2014 | 04/06/2017 | Gold |
| KIN AND CARTA HOLDCO LIMITED | 01552113 | 01/01/2004 | 27/11/2012 | Silver |
| MEDIA CIRCLE TRAINING LIMITED | 03902613 | 15/06/2006 | 30/09/2010 | Gold |
| NATIONAL READERSHIP SURVEYS LIMITED | 02675544 | 01/01/2005 | 31/12/2015 | Amber |
| THE INSTITUTE OF PRACTITIONERS IN ADVERTISING (PRE-CHARTER) | 00221167 | 15/04/2003 | 26/04/2006 | Dissolved |
| ZED MEDIA LIMITED | 03293317 | 26/10/2001 | 31/05/2005 | Dissolved |
| ZENITH SERVICES (MEDIA) LIMITED | 02645326 | 16/03/1998 | 31/05/2005 | One Red Flag |
| ZENITH UK (MEDIA) LIMITED | 01921320 | 16/03/1998 | 31/05/2005 | One Red Flag |