| Company | Timeline | Status | |
| Halcrow Water Services Limited Director • Company Director  | 30 Sep 1998←8 Years→31 Jul 2007  | Dissolved  | |
| Halcrow (Consulting Engineers & Architects) Limited Director • Chartered Engineer  | 1 Sep 1998←8 Years→31 Jul 2007  | Active  | |
| Halcrow Group Limited Director • Chartered Engineer  | 1 Aug 1998←9 Years→31 Jul 2007  | Active  | |
| Sir William Halcrow & Partners Limited Director • Chartered Engineer  | 15 Nov 1991←13 Years→6 Dec 2004  | Dissolved  | |
