| Name | Company Number | Date Appointed | Rating |
|---|---|---|---|
| El Water Management Services Ltd | 02380604 | 15/03/1995 | Dissolved |
| Newcastle & Gateshead Water Co | ZC000066 | 31/07/1991 | Dissolved |
| North East Water Ltd | 02560626 | 28/03/2002 | Dissolved |
| The Water Services Association of England & Wales | 01710723 | 19/12/2000 | Dissolved |
| Name | Company Number | Date Appointed | Date Resigned | Rating |
|---|---|---|---|---|
| AMAZING MEDIA GROUP LIMITED | 06061415 | 09/11/2010 | 05/10/2018 | One Red Flag |
| B.C.S. Garages Ltd | 00812386 | 27/10/1990 | 25/01/1991 | Dissolved |
| BELLWAY P L C | 01372603 | 01/11/2009 | 31/10/2018 | Silver |
| CASTLE VIEW ENTERPRISE ACADEMY | 06268570 | 04/06/2007 | 30/03/2012 | Silver |
| DURHAM COUNTY CRICKET FOUNDATION | 06756096 | 11/01/2011 | 01/07/2015 | One Red Flag |
| DURHAM UNIVERSITY ENTERPRISE LTD | 02830763 | 18/10/2007 | 25/11/2011 | One Red Flag |
| Disco Stores Darlington Ltd | 00724799 | 27/10/1990 | 25/01/1991 | Dissolved |
| ECONOLINER LIMITED | 03255694 | 19/09/1997 | 11/10/2005 | Dissolved |
| ESSEX AND SUFFOLK WATER LIMITED | 02635436 | 20/07/1994 | 31/03/2010 | Silver |
| EUROWATER LIMITED | 02864846 | 22/11/1996 | 20/10/2001 | Gold |
| High Level Motors Ltd | 00573082 | 27/10/1990 | 25/01/1991 | Dissolved |
| IMASS LIMITED | 02379476 | 13/11/1997 | 23/12/2002 | Dissolved |
| LYONNAISE UK WATER SERVICES LIMITED | 01937162 | 20/07/1994 | 23/05/2003 | Dissolved |
| MUSIC NORTH LIMITED | 04344453 | 03/03/2010 | 04/06/2015 | Silver |
| NORTH MUSIC TRUST | 04044936 | 19/03/2010 | 07/03/2018 | Silver |
| NORTHERN BUSINESS FORUM LIMITED | 03718656 | 10/01/2003 | 04/05/2012 | Dissolved |
| NORTHUMBRIAN HOLDINGS LIMITED | 02366698 | 01/11/2001 | 31/03/2010 | Not Trading |
| NORTHUMBRIAN OVERSEAS INVESTMENTS LIMITED | 02820167 | 01/11/2001 | 31/03/2010 | Not Trading |
| NORTHUMBRIAN SERVICES LIMITED | 03114615 | 29/02/1996 | 31/03/2000 | Silver |
| NORTHUMBRIAN WATER FINANCE PLC | 04326507 | 21/11/2001 | 31/03/2010 | Silver |
| NORTHUMBRIAN WATER GROUP LIMITED | 04760441 | 23/05/2003 | 31/03/2010 | Amber |
| NORTHUMBRIAN WATER LIMITED | 02366703 | 01/04/1996 | 31/03/2010 | Amber |
| NORTHUMBRIAN WATER PENSION TRUSTEES LIMITED | 02493044 | 25/04/1991 | 31/03/2010 | Not Trading |
| NORTHUMBRIAN WATER PROJECTS LIMITED | 02528704 | 01/04/2005 | 31/03/2008 | Silver |
| NORTHUMBRIAN WATER SHARE SCHEME TRUSTEES LIMITED | 02331130 | 21/12/2009 | 31/03/2010 | Not Trading |
| Newcastle & Gateshead Water Ltd | 02560617 | 21/07/1992 | 31/01/1997 | Dissolved |
| Newcastle & Sunderland Water Company Limited | 02516537 | 18/11/1994 | 31/01/1997 | Dissolved |
| North East Water Commercial Services Ltd | 02673065 | 17/02/1992 | 31/01/1997 | Dissolved |
| North East Water Ltd | 02560626 | 03/07/1992 | 01/12/1997 | Dissolved |
| Northumbrian Water Technical Centre Ltd | 03310506 | 08/01/1998 | 06/12/2002 | Dissolved |
| Peters & Tomkinson (Darras Hall Garage) Ltd | 00926891 | 27/10/1990 | 25/01/1991 | Dissolved |
| Sunderland & South Shields Water (Trustee) Co Ltd | 00732164 | 19/02/1991 | 31/01/1997 | Dissolved |
| Sunderland and South Shields Water Limited | 02475968 | 21/07/1992 | 31/01/1997 | Dissolved |
| UNITED LIVING WATER LIMITED | 02673066 | 10/03/1992 | 08/07/2005 | Bronze |
| UNITED WATER UK LIMITED | 03198718 | 23/12/2002 | 23/05/2003 | Dissolved |
| UTILITIES AND SERVICE INDUSTRIES TRAINING LIMITED | 01741451 | 09/06/1999 | 16/07/2003 | Dissolved |
| VIGIE UK LIMITED | 02264638 | 01/11/2001 | 23/05/2003 | Bronze |
| WATER COMPANIE'S ASSOCIATION(THE) | 00482134 | 07/07/1993 | 13/05/1999 | Dissolved |
| WATER SERVICES LIMITED | 01923718 | 20/07/1994 | 23/05/2003 | Dissolved |
| WATER UK | 03539600 | 17/04/1998 | 16/11/2005 | Silver |
| WSP ENVIRONMENT & INFRASTRUCTURE SOLUTIONS UK LIMITED | 02190074 | 13/02/2004 | 04/10/2005 | Gold |