| Role | Company | Country | Status | Date Range |
|---|---|---|---|---|
| Officer | PREMIUM CAR BUYING SERVICE LIMITED | 🇬🇧Regno Unito | Active | 08/04/2026 – present |
| Officer | PAARCHER ESTATE AGENT LTD | 🇬🇧Regno Unito | Dissolved | 20/03/2026 – present |
| Officer | M W AUTO CENTRE LIMITED | 🇬🇧Regno Unito | Active | 23/03/2026 – present |
| Officer | AGILE AUDIT ACADEMY LTD | 🇬🇧Regno Unito | Dissolved | 24/03/2026 – present |
| Officer | AGILE OUTSIDE IT LTD | 🇬🇧Regno Unito | Active | 03/02/2026 – present |
| Officer | WILLIAMS GROUP KENT LIMITED | 🇬🇧Regno Unito | Dissolved | 29/03/2026 – present |
| Officer | WE BUILDING SERVICES LTD | 🇬🇧Regno Unito | Active | 18/12/2025 – present |
| Officer | RACING SYNDICATE MANAGEMENT LTD | 🇬🇧Regno Unito | Dissolved | 31/03/2026 – 06/06/2023 |
| Officer | MIDWAY HOLDINGS (STAFFS) LTD | 🇬🇧Regno Unito | Active | 02/02/2026 – present |
| Officer | MARK WILLIAMS INTERNATIONAL LTD | 🇬🇧Regno Unito | Active | 03/04/2026 – 14/10/2021 |
| Officer | THE BIG HEART OF MERTHYR TYDFIL | 🇬🇧Regno Unito | Active | 17/05/2026 – 22/09/2023 |
| Officer | VAN CIRCLE LTD | 🇬🇧Regno Unito | Active | 09/04/2026 – present |
| Officer | TYAS RHYS LTD | 🇬🇧Regno Unito | Dissolved | 01/03/2026 – present |
| Officer | MW ENGINEERING CONSULTANCY LIMITED | 🇬🇧Regno Unito | Dissolved | 01/05/2026 – present |
| Officer | FLEET VEHICLE DISPOSALS LIMITED | 🇬🇧Regno Unito | Active | 15/04/2026 – present |
| Officer | BRYN MENAI AUTOMOTIVE LTD | 🇬🇧Regno Unito | Active | 21/04/2026 – present |
| Officer | MARK WILLIAMS CONSULTANCY SERVICES LTD | 🇬🇧Regno Unito | Active | 08/01/2026 – present |
| Officer | DMJLWILLIAMS LIMITED | 🇬🇧Regno Unito | Dissolved | 25/04/2026 – present |
| Officer | TRADE ASSOCIATIONS SERVICES LIMITED | 🇬🇧Regno Unito | Active | 26/02/2026 – 28/02/2025 |
| Officer | TCM WILLIAMS LIMITED | 🇬🇧Regno Unito | Active | 23/12/2025 – present |
| Officer | WGM MANAGEMENT SERVICES LIMITED | 🇬🇧Regno Unito | Dissolved | 13/05/2026 – present |
| Officer | MARK WILLIAMS (UK) LIMITED | 🇬🇧Regno Unito | Dissolved | 18/05/2026 – present |
| Officer | A & S STORAGE SOLUTIONS LIMITED | — | Dissolved | 21/05/2026 – present |
| Officer | OCEAN CAR CENTRE (TEESSIDE) LTD | 🇬🇧Regno Unito | Dissolved | 22/05/2026 – present |
| Officer | PICARDIE CARPING LIMITED | 🇬🇧Regno Unito | Dissolved | 28/05/2026 – present |
| Officer | TRIPLE M MOTORS LTD | — | Dissolved | 28/05/2026 – 21/08/2012 |
| Officer | TAPDALE LIMITED | — | Dissolved | 02/06/2026 – present |
| Officer | OFF MARKET REALTY UK LTD | — | Active | 04/02/2026 – present |
| Officer | MARK WILLIAMS EXECUTIVE SEARCH (UK) LIMITED | — | Dissolved | 06/06/2026 – present |
| Officer | BROOKSON (5686I) LIMITED | 🇬🇧Regno Unito | Dissolved | 09/06/2026 – present |
| Officer | MIDWAY SURVEYING LIMITED | — | Active | 06/01/2026 – present |
| Officer | M W VEHICLE CONTRACTS LTD | 🇬🇧Regno Unito | Active | 23/03/2026 – present |
| Officer | WILLIAMS BROTHERS LTD | 🇬🇧Regno Unito | Dissolved | 07/01/2026 – present |
02/06/2026
Wales → United Kingdom
28/05/2026
United Kingdom → Wales
31/08/2012
appointed