| Name | Company Number | Date Appointed | Rating |
|---|---|---|---|
| INTERNATIONAL CONSOLIDATED AIRLINES GROUP, S.A. | FC029884 | 01/01/2018 | Amber |
| KELDA EUROBOND CO LIMITED | 06433768 | 09/05/2022 | Silver |
| KELDA FINANCE (NO.2) LIMITED | 08072102 | 25/05/2023 | Silver |
| KELDA GROUP LIMITED | 02366627 | 09/05/2022 | Gold |
| KELDA NON-REG HOLDCO LIMITED | 06433788 | 09/05/2022 | Dissolved |
| KELDA WATER SERVICES LIMITED | 02180706 | 09/05/2022 | Gold |
| LOOP CUSTOMER MANAGEMENT LIMITED | 03816217 | 09/05/2022 | Bronze |
| SALTAIRE WATER LIMITED | 06433802 | 09/05/2022 | Bronze |
| WATER UK | 03539600 | 09/05/2022 | Bronze |
| YORKSHIRE WATER FINANCE PLC | 11444372 | 09/05/2022 | Amber |
| YORKSHIRE WATER SERVICES FINANCE LIMITED | 04636719 | 09/05/2022 | Bronze |
| YORKSHIRE WATER SERVICES HOLDINGS LIMITED | 06815156 | 09/05/2022 | Gold |
| YORKSHIRE WATER SERVICES LIMITED | 02366682 | 09/05/2022 | Silver |
| Name | Company Number | Date Appointed | Date Resigned | Rating |
|---|---|---|---|---|
| CADENT GAS LIMITED | 10080864 | 08/09/2016 | 29/10/2018 | Bronze |
| CCB HOLDINGS LIMITED | 03128545 | 09/03/2009 | 08/06/2010 | Not Trading |
| CCB TV LIMITED | 03187350 | 09/03/2009 | 08/06/2010 | Dissolved |
| CENTREWEST ESOP TRUSTEE (UK) LIMITED | 02907610 | 09/03/2009 | 08/06/2010 | Dissolved |
| CENTREWEST LIMITED | 02844270 | 09/03/2009 | 08/06/2010 | Not Trading |
| CENTREWEST LONDON BUSES LIMITED | 02328596 | 09/03/2009 | 08/06/2010 | Not Trading |
| CONFEDERATION OF PASSENGER TRANSPORT UK | 01182437 | 12/10/2005 | 28/06/2010 | Bronze |
| ENERGY NETWORKS ASSOCIATION LIMITED | 04832301 | 27/02/2019 | 29/10/2021 | Bronze |
| FIRST BEELINE BUSES LIMITED | 02179403 | 09/03/2009 | 08/06/2010 | One Red Flag |
| FIRST BUS HOLDINGS LIMITED | 03261587 | 23/03/2009 | 08/06/2010 | Bronze |
| FIRST CAPITAL EAST LIMITED | 02218277 | 09/03/2009 | 08/06/2010 | Not Trading |
| FIRST CAPITAL NORTH LIMITED | 02636481 | 09/03/2009 | 08/06/2010 | Not Trading |
| FIRSTBUS (NORTH) LIMITED | 03261484 | 23/03/2009 | 08/06/2010 | Silver |
| FIRSTGROUP HOLDINGS LIMITED | 02029363 | 23/01/2006 | 08/06/2010 | Amber |
| FIRSTGROUP PLC | SC157176 | 05/01/2009 | 08/06/2010 | Bronze |
| MAJOR PROJECTS ASSOCIATION | 02157656 | 27/11/2017 | 29/11/2021 | Bronze |
| NATIONAL GAS TRANSMISSION HOLDINGS LIMITED | 03675375 | 27/07/2016 | 05/11/2021 | Amber |
| NATIONAL GAS TRANSMISSION PLC | 02006000 | 27/07/2016 | 05/11/2021 | Silver |
| NATIONAL GRID ELECTRICITY TRANSMISSION PLC | 02366977 | 27/07/2016 | 22/11/2021 | Silver |
| NATIONAL GRID PLC | 04031152 | 01/07/2016 | 26/07/2021 | Silver |
| NGET/SPT UPGRADES LIMITED | 07057886 | 01/01/2017 | 01/11/2021 | One Red Flag |
| QUADGAS HOLDCO LIMITED | 10614254 | 31/03/2017 | 29/10/2018 | Amber |
| QUADGAS MIDCO LIMITED | 10615396 | 31/03/2017 | 29/10/2018 | Amber |
| QUADGAS PLEDGECO LIMITED | 10614954 | 31/03/2017 | 29/10/2018 | Gold |
| TRANSAID WORLDWIDE SERVICES LIMITED | 03511363 | 16/03/2011 | 22/10/2013 | Silver |