| Name | Company Number | Date Appointed | Rating |
|---|---|---|---|
| FIRSTGEN HOLDINGS LTD | 10522500 | 13/12/2016 | Dissolved |
| FIRSTGEN POWER PLC | 07829159 | 31/10/2011 | Dissolved |
| FIRSTGEN UK LTD | 09108643 | 26/03/2015 | Dissolved |
| ICOGEN GUARANTEE LIMITED | 08293819 | 14/11/2012 | Dissolved |
| ICOGEN POWER LIMITED | 08229913 | 26/09/2012 | Dissolved |
| ICOGEN TRADING LIMITED | 08294770 | 15/11/2012 | Dissolved |
| RESERVEGEN UK LIMITED | 09506925 | 24/03/2015 | Dissolved |
| Name | Company Number | Date Appointed | Date Resigned | Rating |
|---|---|---|---|---|
| AES ELECTRIC LTD | 02222066 | 03/11/2009 | 09/03/2010 | Bronze |
| ASHFORD POWER LTD | 09116903 | 04/07/2014 | 12/03/2015 | Silver |
| BEAUFORT POWER LTD | 09111808 | 02/07/2014 | 12/03/2015 | One Red Flag |
| BRECON POWER LTD | 09113303 | 02/07/2014 | 12/03/2015 | One Red Flag |
| FIRSTGEN UK LTD | 09108643 | 30/06/2014 | 12/03/2015 | Dissolved |
| IMMINGHAM ENERGY LIMITED | 03796899 | 23/07/2013 | 31/07/2013 | Gold |
| SALTEND COGENERATION COMPANY LIMITED | 03274929 | 28/07/2005 | 08/08/2007 | Silver |
| SALTEND OPERATIONS COMPANY LIMITED | 04241615 | 28/07/2005 | 08/08/2007 | Bronze |
| VPI ICHP LIMITED | 04047993 | 23/07/2013 | 31/07/2013 | Silver |
| VPI IMMINGHAM OPERATIONS LIMITED | 03716311 | 23/07/2013 | 31/07/2013 | Bronze |
| WEDNESBURY POWER LTD | 09120513 | 08/07/2014 | 12/03/2015 | One Red Flag |
| WOLVERHAMPTON POWER LTD | 09120557 | 08/07/2014 | 12/03/2015 | One Red Flag |