| Thomas Farms (PYG) Ltd | Ruthin | 2026 |
| Thomas Farms Group Wales Ltd | Milford Haven | 2022 |
| Thomas Farms Limited | Langworth | 1974 |
| Thomas Fawcett & SON (Timber) Limited | Pickering | 1966 |
| Thomas Forestry Services Ltd | Selby | 2024 |
| Thomas May's Contracting Limited | Sunbury, Suffolk | 2023 |
| Thomas Ratter Ltd | Shetland | 2016 |
| Thomas Shepherdson Limited | Huddersfield | 2007 |
| Thomas Thomson (Blairgowrie) Limited | Perthshire | 1937 |
| Thomas Trawlers Limited | Cornwall | 2005 |
| Thomas Turf Wales Ltd | Milford Haven | 2022 |
| Thomas Wallis Limited | Hereford | 2011 |
| Thomas Whittle Contracts Limited | Fife | 2006 |
| Thomasson Dairy Ltd | Nantwich | 2019 |
| Thomasson Energy Limited | Nantwich | 2026 |
| Thomasson Livestock Limited | Nantwich | 2025 |
| Thompson Agriculture Limited | Dumbarton | 2026 |
| Thompson Asset Investments Ltd | Crewe | 2024 |
| Thompson Bros. (Esher) Limited | Surrey | 1955 |
| Thompson Cockers Ltd | Chesterfield | 2023 |
| Thompson Farm Ltd | Kesh | 2023 |
| Thompson Farming Limited | East Yorkshire | 2003 |
| Thompson Ground Farm Limited | Preston | 1964 |
| Thompson House Equestrian Centre Limited | Leigh | 2007 |
| Thompson Poultry Limited | Lisburn | 2016 |
| Thompson Rigging & Lifting Services Ltd | Peterhead | 2018 |
| Thompson Tree (Northants) Ltd | Northampton | 2010 |
| Thompson Tree Services (North East) Ltd | Stanley | 2019 |
| Thompson Tree Services (UK) Ltd | Matlock | 2014 |
| Thompson's Walls Limited | Mindrum | 2009 |
| Thompsons Firewood Limited | Ludlow | 2021 |
| Thompsons Nursery Limited | Kent | 1984 |
| Thompsons of Helmsley Limited | North Yorkshire | 2003 |
| Thompsons Plant Hire Limited | Carlisle | 1994 |
| Thomson & Thomson Enterprises Ltd | Derby | 2022 |
| Thomson Brothers Fencing & Forestry Ltd | Kirkmichael | 2022 |
| Thomson Family Farms Limited | Edinburgh | 2016 |
| Thomson Sawmills Holdings Limited | Norwich | 2012 |
| Thomson Straw & Haulage Limited | Wolverhampton | 2015 |
| Thomson Terrace Allotments C.I.C. | Oxford | 2023 |
| Thomson Timber Ltd. | Banchory | 2000 |
| Thomson Timber Services (Perthshire) Ltd | Aberfeldy | 2025 |
| Thomson Tree Services Limited | Warminster | 2000 |
| Thomson Trees Limited | West Linton | 2008 |
| Thorabella Farm Limited | Forres | 2026 |
| Thores Fishing Limited | Peterhead | 2025 |
| Thorington Estate Limited | Saxmundham | 2015 |
| Thormanby Energy Ltd | Thirsk | 2015 |
| Thornacre Ltd | Treharris | 2014 |
| Thornbay Limited | Banff | 2003 |
| Thornber Farms Ltd | Clitheroe | 2016 |
| Thornborrow Farming Ltd | Ayr | 2024 |
| Thornbrook Farm Eggs Ltd | Craigavon | 2016 |
| Thornbury Farms Ltd | Welshpool | 2022 |
| Thornby Farm Holding Ltd | Ilford | 2020 |
| Thornby Farm Limited | Ilford | 2025 |
| Thorncliffe Hall Farm Stables Limited | Stockport | 2007 |
| Thorndon Tree Surgery Ltd | Brentwood | 2024 |
| Thorne and Sons Limited | Market Harborough | 2025 |
| Thorne Timber Company Limited | Edgbaston | 1997 |
| Thorney Beck Nurseries Ltd | Peterborough | 2022 |
| Thorney Moss Game Limited | Spalding | 2011 |
| Thorneycroft Farms Limited | Epwell | 1943 |
| Thorngrove Farm Limited | Worcester | 2020 |
| Thornham Farms (Norfolk) Limited | Hunstanton | 1960 |
| Thornhill Farm (Dorset) Limited | Dorset | 2005 |
| Thornhill Fenwick & Co. | Leeds | 1931 |
| Thornton (EM) Ltd | Melton Mowbray | 2005 |
| Thornton Agri Services Limited | Ravenglass | 2018 |
| Thornton Bridge Farm Ltd | Northallerton | 2016 |
| Thornton Lodge Farm Ltd | Horncastle | 2011 |
| Thornton Park Properties Limited | Thirsk | 1988 |
| Thornton Poultry Limited | Haverfordwest | 2020 |
| Thorntons Farms Limited | Holywood | 2016 |
| Thornyhurst Ltd | Bury | 2023 |
| Thorold Farms Limited | Boston | 1959 |
| Thoroughbed Shavings Limited | Newmarket | 2019 |
| Thoroughbred Transformation Limited | Devizes | 2023 |
| Thoroughbreds in Sport Limited | Newbury | 2023 |
| Thorp Farms Ltd | Sheffield | 2011 |
| Thorpe Bay Fisheries Limited | Basildon | 2007 |
| Thorpe Farm Holdings Limited | Canterbury | 2020 |
| Thorpe Farm Rehabilitation and Fitness Ltd | Northallerton | 2021 |
| Thorpe Farming Limited | Faversham | 2013 |
| Thorpe Green Farm Ltd | Colchester | 2021 |
| Thorpe Lakes Ltd | Cambridge | 2014 |
| Thorpe LEA Fishery Limited | Addlestone | 2008 |
| Thorpe Meadows Ltd | Scunthorpe | 2023 |
| Thorrington Mill Contracting Ltd | Colchester | 2006 |
| Thorsons Farms Limited | Canterbury | 2019 |
| Thortology Ltd | London | 2022 |
| Thos. G. Fairhead Farms Limited | Saffron Walden | 1953 |
| Those Rodds Limited | Bridgwater | 2021 |
| Thow Farms Limited | Laurencekirk | 2000 |
| Three Acre Wood Limited | Sevenoaks | 2015 |
| Three Angels Woodland Farmacy Ltd | Bedford | 2020 |
| Three Ashes Limited | Newmarket | 2011 |
| Three Atop Woodland Services Limited | Minehead | 2022 |
| Three Bears Wood Limited | Southampton | 2021 |
| Three Boys Fishing Limited | Kirkwall | 2023 |