| Company | Timeline | Status | |
| Peter Harrington Us Limited Director • Bookseller  | 1 Jul 2022←3 Years→Current  | Active  | |
| Antiquarian Booksellers Association (International) Director • Bookseller  | 8 Apr 2009←5 Years→23 Apr 2014  | Active  | |
| Peter Harrington Limited Director • Bookseller  | 23 Oct 2003←22 Years→Current  | Active  | |
| Mark Ransom Limited Secretary • Unreported  | 14 Sep 1999←6 Years→24 Oct 2005  | Liquidation  | |
