| Name | Company Number | Date Appointed | Rating |
|---|---|---|---|
| CARD GEOTECHNICS LIMITED | 02993862 | 01/10/2024 | Gold |
| CGL 2014 LIMITED | 08840267 | 01/10/2024 | Gold |
| CONCEPT ENGINEERING CONSULTANTS LTD | 03401367 | 01/10/2024 | Silver |
| CONSTRUCTION TESTING SOLUTIONS GROUP HOLDINGS LIMITED | 05340145 | 01/10/2024 | Gold |
| CONSTRUCTION TESTING SOLUTIONS LIMITED | 05998333 | 01/10/2024 | Bronze |
| G.T. CERTIFICATION LIMITED | 04295617 | 01/10/2024 | Gold |
| IN SITU SITE INVESTIGATION LIMITED | 06339499 | 01/10/2024 | Gold |
| MASON EVANS PARTNERSHIP (HOLDINGS) LIMITED | SC330579 | 01/10/2024 | Amber |
| MASON EVANS PARTNERSHIP LIMITED | SC156317 | 01/10/2024 | Amber |
| N & C 1965 LIMITED | 02911898 | 01/10/2024 | Gold |
| NICHOLLS COLTON GROUP LIMITED | 05605955 | 01/10/2024 | Gold |
| NICHOLLS COLTON LIMITED | 07705902 | 01/10/2024 | Gold |
| PHENNA INFRASTRUCTURE UK LIMITED | 11627758 | 01/10/2024 | Silver |
| SILKSTONE ENVIRONMENTAL LIMITED | 03984219 | 01/10/2024 | Gold |
| THE TESTING GROUP LIMITED | 09430520 | 01/10/2024 | Amber |
| Name | Company Number | Date Appointed | Date Resigned | Rating |
|---|---|---|---|---|
| GRS INTEGRATED SOLUTIONS LIMITED | 04022852 | 19/04/2023 | 31/07/2024 | Amber |