| Name | Company Number | Date Appointed | Rating |
|---|---|---|---|
| KELDA BUFFER LIMITED | 06433787 | 01/04/2010 | Dissolved |
| KELDA HOLDCO LIMITED | 06433799 | 01/04/2010 | Dissolved |
| KELDA JUNIOR HOLDCO LIMITED | 06433796 | 01/04/2010 | Dissolved |
| KELDA PIK CO LIMITED | 06436070 | 01/04/2010 | Dissolved |
| THE YORK WATERWORKS LIMITED | 02511298 | 31/07/2003 | Dissolved |
| York Waterworks Enterprises Ltd | 03050705 | 31/07/2003 | Dissolved |
| Name | Company Number | Date Appointed | Date Resigned | Rating |
|---|---|---|---|---|
| ANCALA WATER SERVICES (DEFENCE) LIMITED | 04617059 | 31/07/2003 | 28/04/2005 | Silver |
| ANCALA WATER SERVICES (ESTATES) LIMITED | 04617130 | 31/07/2003 | 28/04/2005 | Bronze |
| EVANS HOMES (SKELTON) NO.2 LIMITED | 04125370 | 24/09/2013 | 30/10/2018 | Bronze |
| GROSVENOR HOUSE (OTLEY) MANAGEMENT COMPANY LIMITED | 04263360 | 28/04/2006 | 03/07/2008 | Not Trading |
| GROSVENOR HOUSE (OTLEY) MANAGEMENT COMPANY LIMITED | 04263360 | 27/10/2003 | 03/07/2008 | Not Trading |
| KELDA EUROBOND CO LIMITED | 06433768 | 01/04/2010 | 13/09/2019 | Silver |
| KELDA FINANCE (NO.1) LIMITED | 08066326 | 25/06/2012 | 13/09/2019 | Silver |
| KELDA FINANCE (NO.2) LIMITED | 08072102 | 25/06/2012 | 13/09/2019 | Silver |
| KELDA FINANCE (NO.3) PLC | 08270049 | 26/10/2012 | 13/09/2019 | Silver |
| KELDA GROUP LIMITED | 02366627 | 01/04/2010 | 13/09/2019 | Gold |
| KELDA NON-REG HOLDCO LIMITED | 06433788 | 01/04/2010 | 13/09/2019 | Dissolved |
| KELDA WATER SERVICES LIMITED | 02180706 | 01/01/2005 | 23/11/2018 | Gold |
| KEYLAND DEVELOPMENTS LIMITED | 02180728 | 20/05/2010 | 30/10/2018 | Silver |
| LOOP CUSTOMER MANAGEMENT LIMITED | 03816217 | 31/05/2016 | 30/10/2018 | Bronze |
| SALTAIRE WATER LIMITED | 06433802 | 01/04/2010 | 13/09/2019 | Bronze |
| THREE SIXTY WATER LIMITED | 09919590 | 16/12/2015 | 23/11/2018 | Amber |
| THREE SIXTY WATER SERVICES LIMITED | 05612103 | 03/11/2005 | 16/07/2013 | Bronze |
| WATER UK | 03539600 | 01/04/2008 | 31/12/2008 | Silver |
| WATERAID | 01787329 | 14/10/2011 | 13/10/2017 | Silver |
| YORKSHIRE WATER FINANCE PLC | 11444372 | 02/07/2018 | 12/09/2019 | Amber |
| YORKSHIRE WATER SERVICES FINANCE LIMITED | 04636719 | 04/08/2016 | 12/09/2019 | Bronze |
| YORKSHIRE WATER SERVICES HOLDINGS LIMITED | 06815156 | 01/04/2010 | 13/09/2019 | Gold |
| YORKSHIRE WATER SERVICES LIMITED | 02366682 | 31/07/2003 | 13/09/2019 | Silver |