Non-ownership Filings
| £20m Share Buyback Programme | Mar. 10, 2026 |
| Final Results | Mar. 10, 2026 |
| Directorate change | Mar. 04, 2026 |
| Holding(s) in Company | Mar. 03, 2026 |
| Costain returns to FTSE 250 | Mar. 02, 2026 |
| Director Declaration | Feb. 24, 2026 |
| Holding(s) in Company | Feb. 23, 2026 |
Ownership Update Filings
| Director/PDMR Shareholding | Dec. 11, 2025 |
| Holding(s) in Company | Oct. 30, 2025 |
| Holding(s) in Company | Oct. 28, 2025 |
| Holding(s) in Company | Oct. 27, 2025 |
| Holding(s) in Company | Oct. 24, 2025 |
| Holding(s) in Company | Oct. 21, 2025 |
| Holding(s) in Company | Oct. 17, 2025 |