| Name | Company Number | Date Appointed | Rating |
|---|---|---|---|
| 3H INVESTMENTS LIMITED | SC230708 | 24/04/2002 | Silver |
| ABSOLUTE SOLAR AND WIND LTD | SC328796 | 11/03/2022 | Amber |
| ADAS SILVERDALE LIMITED | 11709267 | 03/12/2018 | One Red Flag |
| ADVANTAGE RSK LIMITED | 13660383 | 04/10/2021 | Silver |
| ARA ARCHITECTURE LIMITED | 07729784 | 02/05/2023 | Bronze |
| ATV CONTRACT SERVICES LIMITED | 04515676 | 17/12/2021 | One Red Flag |
| AZERBAIJAN ENVIRONMENT AND TECHNOLOGY CENTRE LIMITED | SC158836 | 23/03/2011 | Amber |
| BTS GROUP LIMITED | 04299486 | 07/12/2018 | One Red Flag |
| CBEC ECO ENGINEERING UK LIMITED | SC385000 | 01/04/2021 | Amber |
| COGNICA LIMITED | 03498533 | 18/08/2020 | Amber |
| CONSENTS SOLUTIONS LTD | 07802798 | 08/04/2019 | Amber |
| CX ENERGY LTD | 11626344 | 31/03/2023 | Amber |
| CX GROUP HOLDINGS LIMITED | 14655804 | 31/03/2023 | Bronze |
| CX UTILITIES LTD | 09620774 | 31/03/2023 | Bronze |
| ECONOMIC RESEARCH SERVICES LIMITED | 02937576 | 31/10/2022 | Silver |
| ENVIRESEARCH LIMITED | 04292592 | 03/03/2021 | Silver |
| ENVIRESEARCH TECHNOLOGIES LIMITED | 11541342 | 03/03/2021 | Bronze |
| ENVIROFLOW MANAGEMENT LIMITED | 07227667 | 15/10/2021 | One Red Flag |
| ENVIROLAB LIMITED | 04487136 | 09/09/2002 | One Red Flag |
| FISHTEK LIMITED | 03749571 | 04/02/2022 | Silver |
| HAWKINS ELECTRICAL HOLDINGS LIMITED | 10697268 | 09/03/2023 | Amber |
| HAWKINS ELECTRICAL LIMITED | 03505136 | 09/03/2023 | Bronze |
| INFORMATION TECHNOLOGISTS LIMITED | SC139749 | 01/01/2007 | Dissolved |
| J & A PELLING LTD | 01062334 | 17/12/2018 | Amber |
| JB SITE INVESTIGATIONS LIMITED | 10057964 | 11/03/2016 | One Red Flag |
| MG SCAFFOLDING (OXFORD) LIMITED | 04543435 | 01/07/2022 | Amber |
| MILESTONE COMMUNICATIONS LIMITED | 05542487 | 04/08/2022 | Amber |
| OPTISOL SERVICES LTD | 10212112 | 16/12/2021 | Bronze |
| PELLING LIMITED | 02551068 | 17/12/2018 | Amber |
| QUANTUM GEOTECHNIC LIMITED | 11892518 | 03/08/2022 | Amber |
| RSK (IRELAND) LIMITED | 05857689 | 23/03/2011 | Amber |
| RSK ADAS LIMITED | 10486936 | 18/11/2016 | Bronze |
| RSK ENVIRONMENT LIMITED | SC115530 | 22/02/1996 | Silver |
| RSK GROUP LIMITED | 03761340 | 26/01/2001 | Amber |
| RSK HI-LINE LIMITED | 13765064 | 25/11/2021 | One Red Flag |
| RSK INVESTMENTS LIMITED | 04500781 | 19/11/2002 | Amber |
| RSK UTILITY CONSULTING LIMITED | 11556909 | 31/03/2023 | Silver |
| SALIX RIVER & WETLAND SERVICES LIMITED | 04944506 | 04/02/2020 | Amber |
| SES STRATEGIC LIMITED | 09231328 | 01/03/2023 | Amber |
| SOUTHERN ECOLOGICAL SOLUTIONS LIMITED | 06192687 | 01/03/2023 | Bronze |
| SPENCER QUANTUM LIMITED | 02928764 | 03/08/2022 | Silver |
| STREETWISE UK MANAGEMENT LIMITED | 05129606 | 15/10/2021 | One Red Flag |
| SUSTAINABLE AQUAFARMS LIMITED | 11791094 | 31/10/2023 | Bronze |
| TBF SCAFFOLDING LTD | 01841098 | 07/12/2018 | Bronze |
| TBF TRAFFIC LTD | 04689212 | 07/12/2018 | Bronze |
| TERRAFFIX SOIL SOLUTIONS LTD | 11795873 | 30/09/2022 | One Red Flag |
| TREEFELLERS LIMITED | 06727099 | 13/12/2022 | Amber |
| TWIG TRADING LIMITED | 04427764 | 26/10/2018 | One Red Flag |
| VIRTUS ENERGY LIMITED | 12080810 | 08/09/2023 | One Red Flag |
| W.CROWDER & SONS LIMITED | 01069525 | 09/06/2023 | Silver |
| WATER RESEARCH CENTRE LIMITED | 11172223 | 18/08/2020 | Bronze |
| WYSE GROUP LIMITED | 05665971 | 16/11/2022 | One Red Flag |
| WYSEPOWER LIMITED | 05379085 | 16/11/2022 | Amber |
| Name | Company Number | Date Appointed | Date Resigned | Rating |
|---|---|---|---|---|
| BTS UTILITY ARB LIMITED | 05597917 | 07/12/2018 | 21/05/2021 | Dissolved |
| KAZAKHSTAN ENVIRONMENT AND TECHNOLOGY CENTRE LIMITED | 04432551 | 01/01/2007 | 21/05/2021 | Dissolved |
| R.W. MANAGEMENT (HOLDINGS) LTD | 03846486 | 30/06/2003 | 21/05/2021 | Dissolved |
| RSK CARTER ECOLOGICAL LTD | 06138360 | 23/03/2011 | 21/05/2021 | Dissolved |
| RSK ENVIRONMENT (EASTERN EUROPE) LIMITED | 05056397 | 26/02/2011 | 21/05/2021 | Dissolved |
| RSK RESOURCING LIMITED | 06000032 | 01/12/2008 | 21/05/2021 | Dissolved |
| SPENCER ECA GROUP LIMITED | 12025776 | 03/08/2022 | 01/03/2024 | Dissolved |
| SUSTAINABLE PIGMENTS LIMITED | 03446438 | 08/09/2020 | 21/05/2021 | Dissolved |
| TBF CONTRACTING LIMITED | 09762168 | 07/12/2018 | 01/03/2024 | Dissolved |
| TECHNICAL EDITING SERVICES LIMITED | 02928662 | 23/03/2011 | 21/05/2021 | Dissolved |