| Name | Company Number | Date Appointed | Rating |
|---|---|---|---|
| Amtec Bunting Ltd | 01847776 | 05/05/2000 | Dissolved |
| Coquetdale Property Investment Ltd | 02379478 | 30/06/2006 | Dissolved |
| El Water Management Services Ltd | 02380604 | 09/02/2001 | Dissolved |
| Hydrotechnical Services (International) Ltd | 01653089 | 05/05/2000 | Dissolved |
| Jayhold Ltd | 01945410 | 30/06/2000 | Dissolved |
| Northumbrian Gould Group Ltd | 00785518 | 24/09/1993 | Dissolved |
| Northumbrian Gould Group Ltd | 00785518 | 31/03/2006 | Dissolved |
| Northumbrian International Holdings Ltd | 02489304 | 30/06/2000 | Dissolved |
| Northumbrian International Holdings Ltd | 02489304 | 01/07/2001 | Dissolved |
| Northumbrian Water Estates Ltd | 02090716 | 05/05/2000 | Dissolved |
| Renovexx Technology Ltd | 02569076 | 17/12/1992 | Dissolved |
| Renovexx Technology Ltd | 02569076 | 25/01/2002 | Dissolved |
| Rural Building Consultants | 00803749 | 05/05/2000 | Dissolved |
| St. Mary's Court Leasing Ltd | 01579859 | 30/06/2000 | Dissolved |
| Waterco Four Ltd | 02598745 | 05/05/2000 | Dissolved |
| Waterco Nine Ltd | 00961691 | 05/05/2000 | Dissolved |
| Waterco One Ltd | 01803780 | 13/10/1992 | Dissolved |
| Waterco One Ltd | 01803780 | 05/05/2000 | Dissolved |
| Name | Company Number | Date Appointed | Date Resigned | Rating |
|---|---|---|---|---|
| ANALYTICAL & ENVIRONMENTAL SERVICES LIMITED | 02379517 | 17/02/1994 | 08/10/2021 | Not Trading |
| ANALYTICAL & ENVIRONMENTAL SERVICES LIMITED | 02379517 | 05/05/2000 | 08/10/2021 | Not Trading |
| ANGLIAN WATER BUSINESS (NATIONAL) LIMITED | 03017251 | 19/04/2018 | 08/10/2021 | Silver |
| CASTLE VIEW COMMUNITY AND FITNESS CENTRE LIMITED | 06873681 | 18/08/2009 | 01/02/2013 | Insolvent |
| CASTLE VIEW ENTERPRISE ACADEMY | 06268570 | 04/06/2007 | 22/03/2013 | Silver |
| DURHAM STUDENTS' UNION | 07689815 | 01/09/2015 | 06/03/2019 | Gold |
| ESSEX AND SUFFOLK WATER LIMITED | 02635436 | 09/02/2001 | 08/10/2021 | Silver |
| ESSEX AND SUFFOLK WATER LIMITED | 02635436 | 28/03/2002 | 08/10/2021 | Silver |
| NORTHUMBRIAN HOLDINGS LIMITED | 02366698 | 11/07/2005 | 08/10/2021 | Not Trading |
| NORTHUMBRIAN HOLDINGS LIMITED | 02366698 | 24/03/2016 | 08/10/2021 | Not Trading |
| NORTHUMBRIAN OVERSEAS INVESTMENTS LIMITED | 02820167 | 30/06/2000 | 08/10/2021 | Not Trading |
| NORTHUMBRIAN SERVICES LIMITED | 03114615 | 17/06/2003 | 08/10/2021 | Silver |
| NORTHUMBRIAN SERVICES LIMITED | 03114615 | 24/03/2016 | 17/10/2016 | Silver |
| NORTHUMBRIAN WATER FINANCE PLC | 04326507 | 21/11/2001 | 08/10/2021 | Silver |
| NORTHUMBRIAN WATER FINANCE PLC | 04326507 | 28/05/2020 | 08/10/2021 | Silver |
| NORTHUMBRIAN WATER GROUP LIMITED | 04760441 | 23/05/2003 | 08/10/2021 | Amber |
| NORTHUMBRIAN WATER LIMITED | 02366703 | 01/04/2000 | 08/10/2021 | Amber |
| NORTHUMBRIAN WATER MEXICO LIMITED | 03078662 | 30/06/2002 | 08/10/2021 | Not Trading |
| NORTHUMBRIAN WATER PENSION TRUSTEES LIMITED | 02493044 | 30/06/2002 | 08/10/2021 | Not Trading |
| NORTHUMBRIAN WATER PENSION TRUSTEES LIMITED | 02493044 | 25/06/2001 | 08/10/2021 | Not Trading |
| NORTHUMBRIAN WATER PROJECTS LIMITED | 02528704 | 30/06/2000 | 31/03/2008 | Silver |
| NORTHUMBRIAN WATER SHARE SCHEME TRUSTEES LIMITED | 02331130 | 05/01/2004 | 08/10/2021 | Not Trading |
| NORTHUMBRIAN WATER SHARE SCHEME TRUSTEES LIMITED | 02331130 | 29/04/2015 | 08/10/2021 | Not Trading |
| NTC TOURING THEATRE COMPANY LTD | 01448366 | 26/01/1997 | 29/06/2011 | Bronze |
| NWG COMMERCIAL SOLUTIONS LIMITED | 10028815 | 23/03/2016 | 30/05/2020 | Silver |
| REIVER FINANCE LIMITED | 04872988 | 30/09/2003 | 08/10/2021 | Silver |
| REIVER FINANCE LIMITED | 04872988 | 22/05/2020 | 08/10/2021 | Silver |
| REIVER HOLDINGS LIMITED | 04872994 | 30/09/2003 | 08/10/2021 | Gold |
| REIVER HOLDINGS LIMITED | 04872994 | 22/05/2020 | 08/10/2021 | Gold |
| WATERCO SIX LIMITED | 02528693 | 07/08/1992 | 20/10/2006 | Not Trading |
| WATERCO SIX LIMITED | 02528693 | 01/04/2013 | 08/10/2021 | Not Trading |
| WAVE LTD | 06492265 | 31/08/2017 | 08/10/2021 | Silver |
| WAVE UTILITIES LIMITED | 04047470 | 04/08/2000 | 29/10/2014 | Not Trading |
| WAVE UTILITIES LIMITED | 04047470 | 19/04/2018 | 08/10/2021 | Not Trading |