| Name | Company Number | Date Appointed | Rating |
|---|---|---|---|
| A14 ENERGY LIMITED | 15010011 | 25/08/2023 | Bronze |
| DART ENERGY (EAST ENGLAND) LIMITED | 06760546 | 31/07/2020 | One Red Flag |
| DART ENERGY (EUROPE) LIMITED | SC259898 | 31/07/2020 | Gold |
| DART ENERGY (WEST ENGLAND) LIMITED | 06760557 | 31/07/2020 | Amber |
| EOLAS UK CONSULTING LIMITED | 09941084 | 07/01/2016 | Silver |
| GT ENERGY CROATIA LIMITED | 15019171 | 21/07/2023 | Bronze |
| GT ENERGY UK LIMITED | 08451346 | 29/03/2023 | One Red Flag |
| IGAS ENERGY DEVELOPMENT LIMITED | 07240286 | 31/07/2020 | Bronze |
| IGAS ENERGY ENTERPRISE LIMITED | 05457589 | 31/07/2020 | Bronze |
| IGAS ENERGY LIMITED | 05054503 | 31/07/2020 | Gold |
| IGAS ENERGY PRODUCTION LIMITED | SC298739 | 31/07/2020 | Bronze |
| ISLAND GAS (SINGLETON) LIMITED | 01021095 | 31/07/2020 | Gold |
| ISLAND GAS LIMITED | 04962079 | 31/07/2020 | Bronze |
| ISLAND GAS OPERATIONS LIMITED | 03999194 | 31/07/2020 | Not Trading |
| STAR ENERGY GROUP PLC | 04981279 | 14/09/2022 | Amber |
| STAR ENERGY LIMITED | 03806814 | 31/07/2020 | Amber |
| STAR ENERGY WEALD BASIN LIMITED | 06293763 | 31/07/2020 | Bronze |
| Name | Company Number | Date Appointed | Date Resigned | Rating |
|---|---|---|---|---|
| NEXEN ENERGY MARKETING EUROPE LIMITED | 05566335 | 21/08/2014 | 26/06/2015 | Dissolved |