| Company | Timeline | Status | |
| Ralted Limited Director • Consultant | 13 Jan 2015←10 Years→Current | Active | |
| The Dairy Meadow Residents Management Company Limited Director • Town Planner | 15 Jan 1999←2 Years 3 Months→26 Apr 2001 | Active | |
| Buchanan Computing Limited Director • Director | 6 Nov 1996←11 Years→7 Mar 2008 | Active | |
| Colin Buchanan And Partners Limited Director • Company Director | 28 Sep 1991←19 Years→2 Jun 2011 | Dissolved | |
