- Thomas, Carroll Private Clients Ltd - London
- Thomas, Carroll Properties Ltd - Caerphilly
- Thomas, Carroll Special Risks Ltd - Caerphilly
- Thomas, David Sons & Co Ltd - Neath
- Thomas, E. & Williams Ltd - Aberdare
- Thomas, E. Construction - Truro
- Thomas, Hefin - Agricultural Contractors - Tyn-y-Gongl
- Thomas, Keith Ltd - Malvern
- Thomas, Morgan & Associates Ltd - Pontypridd
- Thomas, P R & Co - Arthog
- Thomas, Richard Associates - Penarth
- Thomas,mills & Co.,limited - Bridgend
- Thomas-byron Associates Ltd - Chessington
- Thomas-davies & Company (London) Ltd - Stansted
- Thomas-hammond Ltd - Reading
- Thomas-hunte Solutions Ltd - Swansea
- Thomas-kidd Ltd - Windsor
- Thomas-knott Ltd - Birmingham
- Thomas-lewis (UK) Ltd - St. Austell
- Thomas-mckay Ltd - Brackley
- Thomas-mitchell Trading Ltd - Worthing
- THOMAS-RICHARDSON MANAGEMENT GROUP LTD - Kingswinford
- Thomas-smith Consulting Ltd - Newquay
- Thomas. Bergin - Harrow
- ThomasBlakemore Ltd - Walsall