| Name | Company Number | Date Appointed | Rating |
|---|---|---|---|
| ARMSTRONG ENERGY IHT GROWTH PLC | 08801340 | 06/02/2014 | Dissolved |
| ARMSTRONG ENERGY IHT INCOME PLC | 08801341 | 06/02/2014 | Dissolved |
| PKD CONSULTANTS LIMITED | 14219080 | 06/07/2022 | Bronze |
| Name | Company Number | Date Appointed | Date Resigned | Rating |
|---|---|---|---|---|
| ATKINSRÉALIS UK INTERNATIONAL LIMITED | 01091953 | 01/04/2009 | 31/05/2010 | Silver |
| ATKINSRÉALIS UK LIMITED | 00688424 | 01/04/2009 | 31/05/2010 | Silver |
| WSP ENVIRONMENTAL LIMITED | 01152332 | 24/09/2012 | 15/12/2016 | Dissolved |
| WSP GROUP LIMITED | 02136404 | 01/06/2010 | 17/12/2020 | Gold |
| WSP HOLDING UK LIMITED | 08100508 | 19/06/2014 | 17/12/2020 | Silver |
| WSP MANAGEMENT SERVICES LIMITED | 02454665 | 29/07/2010 | 15/12/2016 | Silver |
| WSP UK LIMITED | 01383511 | 29/07/2010 | 15/12/2016 | Gold |