| Name | Company Number | Date Appointed | Rating |
|---|---|---|---|
| Bellevue Consultants (U K) Ltd | 02096300 | 24/10/2003 | Dissolved |
| CARRIG STONE CONSULTANTS UK LIMITED | 04707074 | 21/03/2003 | Dissolved |
| LONDON & STROUD LIMITED | 03916342 | 31/01/2000 | Dissolved |
| RYBKA SMITH GINSLER AND BATTLE LONDON LIMITED | 02526071 | 09/09/2009 | Dissolved |
| Strategic Fire Engineering Ltd | 04833583 | 15/07/2003 | Dissolved |
| THE WHITBYBIRD FOUNDATION | 06849934 | 17/03/2009 | Silver |
| The-E-Shop.Co.Uk Ltd | 03948166 | 06/04/2001 | Dissolved |
| Whitby & Bird Mep Ltd | 05678763 | 18/01/2006 | Dissolved |
| Whitbybird Environmental Ltd | 05972032 | 19/10/2006 | Dissolved |
| Whitbybird International Ltd. | 05105840 | 19/04/2004 | Dissolved |
| Whitbybird Middle East Ltd. | 05104988 | 19/04/2004 | Dissolved |
| Name | Company Number | Date Appointed | Date Resigned | Rating |
|---|---|---|---|---|
| 03834250 LIMITED | 03834250 | 18/10/1999 | 09/09/2021 | Dissolved |
| CES PROPERTIES (HEMEL HEMPSTEAD) LIMITED | 02997640 | 15/12/1994 | 10/11/1995 | Silver |
| ELEMENT ENERGY LIMITED | 04646003 | 23/01/2003 | 16/06/2010 | Insolvent |
| ENGINEERING TIMELINES | 04964786 | 14/11/2003 | 05/03/2012 | Amber |
| HACKNEY HISTORIC BUILDINGS TRUST(THE) | 01879857 | 22/02/2001 | 16/01/2003 | Silver |
| HACKNEY HISTORIC BUILDINGS TRUST(THE) | 01879857 | 01/06/1992 | 16/01/2003 | Silver |
| OWNPOWER UK LIMITED | 04919208 | 02/10/2003 | 04/10/2010 | Not Trading |
| RAMBOLL MIDDLE EAST LIMITED | 02019473 | 02/12/2002 | 20/06/2019 | Amber |
| RAMBOLL UK HOLDING LIMITED | 06322436 | 26/09/2007 | 20/06/2019 | Not Trading |
| RAMBOLL UK LIMITED | 03659970 | 01/10/2000 | 20/06/2019 | Gold |
| RAMBOLL WHITBYBIRD HOLDINGS LIMITED | 04079634 | 27/02/2002 | 20/06/2019 | Not Trading |
| SANDOR HOLDINGS LIMITED | 03039087 | 29/03/1995 | 10/11/1995 | Bronze |
| SANDOR PROPERTY MANAGEMENT SERVICES LIMITED | 03037552 | 28/03/1995 | 10/11/1995 | Bronze |
| TIDALSTREAM LIMITED | 06593601 | 15/09/2010 | 10/06/2011 | Dissolved |