| Name | Company Number | Date Appointed | Rating |
|---|---|---|---|
| EUROCOM (U.K.) LIMITED | 02520082 | 21/09/1996 | Dissolved |
| Metis Consulting Ltd | 02916068 | 07/04/1995 | Dissolved |
| OXFORD ELECTROMAGNETIC SOLUTIONS LIMITED | 07246605 | 01/06/2013 | Amber |
| WATERSHED ASSOCIATES LIMITED | 06016832 | 04/12/2006 | Silver |
| Name | Company Number | Date Appointed | Date Resigned | Rating |
|---|---|---|---|---|
| ENVIRO-FRESH LIMITED | 04014649 | 16/06/2003 | 31/12/2004 | Not Trading |
| INSTITUTE OF WATER | 00539193 | 20/06/2018 | 09/09/2024 | Gold |
| NORTH SURREY WATER LIMITED | 02664524 | 01/04/2000 | 11/10/2000 | Dissolved |
| REDR UK | 03929653 | 07/03/2000 | 24/10/2005 | Bronze |
| THE PIPELINE INDUSTRIES GUILD LIMITED | 02563351 | 18/06/2008 | 24/06/2014 | Silver |
| WOMEN'S ENGINEERING SOCIETY | 00162096 | 27/01/1992 | 19/09/1993 | Gold |