| Company | Timeline | Status | |
| Costain Upstream Limited Director • Chartered Accountant | 18 Dec 2020←1 Year 3 Months→18 Mar 2022 | Active | |
| Costain Integrated Technology Solutions Limited Director • Chartered Accountant | 30 Nov 2020←1 Year 3 Months→18 Mar 2022 | Active | |
| Brunswick Infrastructure Services Limited Director • Chartered Accountant | 1 Sep 2020←1 Year 6 Months→18 Mar 2022 | Dissolved | |
| Calvert & Russell Ltd Director • Chartered Accountant | 1 Sep 2020←1 Year 6 Months→18 Mar 2022 | Active | |
| Construction Study Centre Limited Director • Chartered Accountant | 1 Sep 2020←1 Year 6 Months→18 Mar 2022 | Active | |
| Costain Engineering & Construction (Overseas) Limited Director • Chartered Accountant | 1 Sep 2020←1 Year 6 Months→18 Mar 2022 | Active | |
| Costain Alcaidesa Limited Director • Chartered Accountant | 1 Sep 2020←1 Year 6 Months→18 Mar 2022 | Dissolved | |
| Costain Integrated Services Limited Director • Chartered Accountant | 1 Sep 2020←1 Year 6 Months→18 Mar 2022 | Active | |
| Costain Oil, Gas & Process (Overseas) Limited Director • Chartered Accountant | 1 Sep 2020←1 Year 6 Months→18 Mar 2022 | Active | |
| Westminster Plant Co. Limited Director • Chartered Accountant | 1 Sep 2020←1 Year 6 Months→18 Mar 2022 | Dissolved | |
