| Name | Company Number | Date Appointed | Rating |
|---|---|---|---|
| CH2M HILL EUROPE LIMITED | 07262036 | 11/08/2021 | One Red Flag |
| CH2M HILL HOLDINGS LIMITED | 12661700 | 11/08/2021 | One Red Flag |
| CH2M HILL ONE LIMITED | 12661623 | 11/08/2021 | Strike Off |
| CH2M HILL SERVICES LIMITED | 04263139 | 11/08/2021 | Strike Off |
| CH2M HILL UNITED KINGDOM | 02533469 | 11/08/2021 | Silver |
| GIBB HOLDINGS LTD | 02387714 | 11/08/2021 | Dissolved |
| HALCROW (CONSULTING ENGINEERS & ARCHITECTS) LIMITED | 01045458 | 11/08/2021 | Amber |
| HALCROW ASIA LIMITED | 02458827 | 11/08/2021 | One Red Flag |
| HALCROW ASIA PARTNERSHIP LIMITED | 02490667 | 11/08/2021 | One Red Flag |
| HALCROW CANADA LIMITED | 05296410 | 11/08/2021 | Dissolved |
| HALCROW CONSULTING LIMITED | 02326761 | 11/08/2021 | One Red Flag |
| HALCROW GROUP LIMITED | 03415971 | 11/08/2021 | Amber |
| HALCROW HOLDINGS LIMITED | 01674044 | 11/08/2021 | One Red Flag |
| HALCROW INTERNATIONAL LIMITED | 02326765 | 13/08/2021 | Amber |
| HALCROW INTERNATIONAL PARTNERSHIP | 02809680 | 11/08/2021 | Amber |
| JACOBS CANADA (UK) LIMITED | 14089240 | 05/05/2022 | Strike Off |
| JACOBS ENGINEERING UK LIMITED | 02527622 | 11/08/2021 | Dissolved |
| JACOBS EUROPE HOLDCO LIMITED | 09188414 | 11/08/2021 | Bronze |
| JACOBS FOUR LTD | 11041435 | 21/09/2023 | Bronze |
| JACOBS ONE LIMITED | SC141100 | 11/08/2021 | Gold |
| JACOBS SINGAPORE (UK) LIMITED | 14094582 | 09/05/2022 | Strike Off |
| JACOBS TWO LIMITED | SC580155 | 11/08/2021 | Bronze |
| JACOBS U.K. LIMITED | 02594504 | 09/12/2020 | Bronze |
| JACOBS UK HOLDINGS LIMITED | 04420029 | 11/08/2021 | Gold |
| JACOBSGIBB LTD | 02387707 | 11/08/2021 | Silver |
| LEIGHFISHER HOLDINGS LIMITED | 07462876 | 11/08/2021 | Dissolved |
| LEIGHFISHER LIMITED | 02591354 | 11/08/2021 | Silver |
| LEIGHFISHER U.K. LIMITED | 02653755 | 11/08/2021 | Dissolved |
| RINGWAY JACOBS LIMITED | 05576465 | 26/10/2023 | Silver |
| SIR WILLIAM HALCROW & PARTNERS LIMITED | 01722541 | 11/08/2021 | Strike Off |
| TRANSMARK ASIA LIMITED | 02815214 | 11/08/2021 | One Red Flag |
| Name | Company Number | Date Appointed | Date Resigned | Rating |
|---|---|---|---|---|
| AMENTUM CLEAN ENERGY LIMITED | 01120437 | 26/06/2020 | 01/12/2021 | Bronze |
| AMENTUM E&C LIMITED | 04967961 | 03/06/2019 | 01/12/2021 | Silver |
| AMENTUM ENTERPRISE ASSET SOLUTIONS CONSTRUCTION LIMITED | 08584259 | 30/11/2020 | 01/12/2021 | Silver |
| AMENTUM ENTERPRISE ASSET SOLUTIONS LIMITED | 01172655 | 30/11/2020 | 01/12/2021 | One Red Flag |
| AMENTUM INTERNATIONAL NUCLEAR SERVICES LIMITED | 05532606 | 03/06/2019 | 01/12/2021 | Silver |
| FAST REACTOR TECHNOLOGY LIMITED | 01853864 | 26/06/2020 | 01/12/2021 | Not Trading |
| L.E.S. CONSTRUCTION LIMITED | 02857923 | 30/11/2020 | 01/12/2021 | Dissolved |
| LEIGHFISHER HOLDINGS LIMITED | 07462876 | 01/06/2011 | 23/10/2013 | Dissolved |
| LEIGHFISHER LIMITED | 02591354 | 01/06/2011 | 23/10/2013 | Silver |
| PWR POWER PROJECTS LIMITED | 02281663 | 26/06/2020 | 01/12/2021 | Gold |