| SONIC SYSTEMS LIMITED | Electrical equipment | 1984 | Total exemption (full) |
| LOXSTON GROUNDCARE LIMITED | Repair and installation of machinery | 1994 | Total exemption (full) |
| MINSTERSTONE LIMITED | Glass, ceramics, cement and stone | 1995 | Total exemption (full) |
| BEADON SOLUTIONS LIMITED | Computers, electronics and optics | 1999 | Total exemption (full) |
| KENT PERISCOPES LIMITED | Computers, electronics and optics | 2005 | Audit-exempt subsidiary |
| THE PATRIOT BREWERY LIMITED | Beverages | 2009 | Total exemption (full) |
| KNIGHT ELECTRICAL SWITCHGEAR LTD. | Electrical equipment | 2010 | Total exemption (full) |