| Name | Company Number | Date Appointed | Rating |
|---|---|---|---|
| ASPECT CLARK LTD | 15213428 | 16/10/2023 | Bronze |
| BCT REALISATIONS 2018 LIMITED | 04145482 | 01/01/2016 | Dissolved |
| ISLE GROUP LIMITED | 09805763 | 02/10/2015 | Silver |
| OZO INNOVATIONS LIMITED | 08071406 | 18/11/2016 | One Red Flag |
| Water Science Ltd | 04682761 | 22/02/2007 | Dissolved |
| Name | Company Number | Date Appointed | Date Resigned | Rating |
|---|---|---|---|---|
| ATKINSRÉALIS CONSULTANTS LIMITED | 00755613 | 24/02/2003 | 31/10/2005 | Dissolved |
| ATKINSRÉALIS UK INTERNATIONAL LIMITED | 01091953 | 24/02/2003 | 31/10/2005 | Silver |
| BLUEWATER BIO LIMITED | 06101644 | 15/03/2010 | 23/03/2012 | Silver |
| BRITISH WATER | 03953229 | 23/10/2002 | 19/03/2003 | Gold |
| FOUDRY PROPERTIES LIMITED | 04551073 | 19/12/2011 | 12/12/2014 | One Red Flag |
| INNOVA PARK MANAGEMENT COMPANY LIMITED | 03080140 | 31/01/2012 | 12/12/2014 | One Red Flag |
| ISLE UTILITIES LIMITED | 07140964 | 29/01/2010 | 21/02/2024 | Silver |
| KENNET PROPERTIES LIMITED | 02498997 | 31/01/2012 | 12/12/2014 | One Red Flag |
| KIER RAIL LIMITED | 03050424 | 01/09/2008 | 31/12/2009 | Not Trading |
| MOUCHEL LIMITED | 01686040 | 01/11/2005 | 31/12/2009 | Bronze |
| Mouchel Parkman Rail Ltd | 06450653 | 01/09/2008 | 01/09/2008 | Dissolved |
| PARKMAN CONSULTANTS LIMITED | 01165456 | 19/05/2007 | 31/12/2009 | Not Trading |
| Quay Environmental Ltd | 04541045 | 20/09/2002 | 31/03/2004 | Dissolved |
| RENTRICITY LIMITED | 06064150 | 07/03/2007 | 31/12/2009 | Dissolved |
| SHAPESHARE LIMITED | 04389988 | 31/01/2012 | 12/12/2014 | Dissolved |
| SONICO LIMITED | 04378399 | 26/06/2002 | 06/09/2005 | Dissolved |
| THAMES WATER COMMERCIAL SERVICES LIMITED | 08021020 | 05/04/2012 | 12/12/2014 | One Red Flag |
| THAMES WATER COMMERCIAL VENTURES FINANCE LIMITED | 08766303 | 07/11/2013 | 12/12/2014 | One Red Flag |
| THAMES WATER COMMERCIAL VENTURES HOLDINGS LIMITED | 08765700 | 07/11/2013 | 12/12/2014 | Amber |
| THAMES WATER DEVELOPMENTS LIMITED | 02638323 | 31/01/2012 | 12/12/2014 | Dissolved |
| THAMES WATER INVESTMENTS LIMITED | 02567126 | 31/01/2012 | 12/12/2014 | Silver |
| THAMES WATER PROPERTY SERVICES LIMITED | 02606112 | 31/01/2012 | 12/12/2014 | One Red Flag |
| UK WATER INDUSTRY RESEARCH LIMITED | 02862807 | 10/09/2010 | 21/10/2010 | Bronze |
| WATER AND SANITATION FOR THE URBAN POOR | 05419428 | 27/10/2011 | 21/11/2013 | Bronze |
| WMSCG LIMITED | 03611611 | 16/11/2006 | 04/06/2007 | Dissolved |
| ZEROPEX UK LIMITED | 07153857 | 22/02/2010 | 01/09/2011 | Dissolved |