| Tregenna Gardens Ltd | Construction | 2020 |
| Tregenna Group Ltd | Professional & scientific | 2023 |
| Tregenna O&S (SPV 15) Ltd | Construction | 2022 |
| Tregenna Properties - Developments (SPV) 11 Ltd | Construction | 2022 |
| Tregenna Properties - Developments (SPV) 12 Ltd | Construction | 2022 |
| Tregenna Properties - Developments (SPV) 14 Ltd | Construction | 2022 |
| Tregenna Properties - Developments (SPV) 16 Ltd | Construction | 2024 |
| Tregenna Properties - Developments (SPV) 17 Ltd | Construction | 2024 |
| Tregenna Properties - Developments (SPV) 18 Ltd | Construction | 2024 |
| Tregenna Properties - Developments (SPV) 19 Ltd | Construction | 2025 |
| Tregenna Properties - Developments (SPV) 2 Ltd | Construction | 2018 |
| Tregenna Properties - Developments (SPV) 4 Ltd | Construction | 2019 |
| Tregenna Properties - Developments (SPV) 6 Ltd | Real estate | 2019 |
| Tregenna Properties - Developments (SPV) 7 Ltd | Construction | 2020 |
| Tregenna Properties - Developments (SPV) 8 Ltd | Construction | 2021 |
| Tregenna Properties - Developments (SPV) 9 Ltd | Construction | 2022 |
| Tregenna Properties Ltd | Construction | 2017 |
| Tregenna Surgical Care Limited | Health & social care | 2019 |
| Tregenna Ventures Limited | Information & communication | 2014 |
| Trellis Direct Limited | Extraterritorial | 2011 |
| Trent Court Management Company Limited | Households | 1986 |
| Trents Farm Churchinford Management Company Limited | Households | 2003 |
| Tresco Toose Management Company Limited | Households | 2002 |
| Tresonic Limited | Information & communication | 2025 |
| Trethurffe Meadows Limited | Construction | 2017 |
| Trevanion House Holidays Ltd | Hospitality | 2002 |
| Trevinia Limited | Professional & scientific | 2018 |
| Trevor J Spurway (Architect) Limited | Professional & scientific | 1988 |
| Trevow Ltd | Other services | 2024 |
| Trewiston Farm Caravans Limited | Hospitality | 2014 |
| Treyarnon Investments Limited | Financial services | 2019 |
| TRG Lawrence & SON Taunton Limited | Real estate | 2014 |
| Triangle Property Company Taunton Limited | Real estate | 2017 |
| Triarc Group Limited | Administrative & support | 2023 |
| Triark Limited | Administrative & support | 2024 |
| Trickey Warren Management Company Ltd | Real estate | 2005 |
| Tricky Dicky Enterprises Ltd | Hospitality | 2024 |
| Trigo Investments Ltd | Financial services | 2025 |
| Trinity Court (Yeovil) Limited | Households | 2003 |
| Trinity Court Management Company (Taunton) Limited | Households | 1995 |
| Trinity Farm Seagry Limited | Agriculture & fishing | 2005 |
| Trinity Gate Bridgwater Management Company Number One Limited | Households | 2005 |
| Trinity Way Minehead Management Limited | Households | 2002 |
| Triple Aqua Consulting Limited | Professional & scientific | 2018 |
| Triple Aqua Licensing Limited | Water & waste | 2013 |
| Triscombe Brewery Ltd | Manufacturing | 2021 |
| Triscombe Estate Ltd | Agriculture & fishing | 2022 |
| Triscombe Neurology Ltd | Health & social care | 2020 |
| Triskelion Executive Ltd | Professional & scientific | 2023 |
| Tristan Pengelley Limited | Information & communication | 2018 |
| Triton TS Limited | Information & communication | 2010 |
| TRO Medical Limited | Health & social care | 2026 |
| Trollman Ltd | Real estate | 2019 |
| Trollope-Bellew Estates Ltd | Real estate | 2024 |
| Tropical HUT Ltd | Hospitality | 2018 |
| Trowbridge Farming Ltd | Agriculture & fishing | 2021 |
| TRP Research Ltd | Professional & scientific | 1999 |
| Truck & BUS Builder Publishing Limited | Information & communication | 1991 |
| Truck & BUS Builder Reports Limited | Information & communication | 2001 |
| Truck Tech Yorkshire Limited | Wholesale & retail | 2021 |
| Truckles Limited | Extraterritorial | 2006 |
| True Skincare Limited | Wholesale & retail | 2018 |
| Truepoint Properties Ltd | Real estate | 2025 |
| Trull Car Sales Ltd | Wholesale & retail | 2025 |
| Trull Foot Health Care Ltd | Health & social care | 2026 |
| Trull Green Ltd | Real estate | 2026 |
| Trull Lawn Tennis Club Limited | Arts & recreation | 1962 |
| Truly Creative Limited | Information & communication | 2014 |
| Trust Inventory Ltd | Other services | 2018 |
| Trust Rail Solutions Ltd | Professional & scientific | 2014 |
| Trusted Service Ltd | Extraterritorial | 2019 |
| Trutt Ltd | Arts & recreation | 2020 |
| TRX Services Ltd | Transport & logistics | 2019 |
| Trymata Developments Ltd | Extraterritorial | 2018 |
| Trymata Holdings Limited | Financial services | 2023 |
| Trymata Services Limited | Construction | 2016 |
| Tson Services Ltd | Wholesale & retail | 2020 |
| Tsunami Holdings Company Ltd | Financial services | 2020 |
| Tszc Limited | Hospitality | 2023 |
| TTA Trading Ltd | Hospitality | 2014 |
| TTC66 Ltd | Financial services | 2025 |
| Ttcf Ltd | Arts & recreation | 2017 |
| Ttga+ Ltd | Arts & recreation | 2024 |
| TTM Hearing Services Ltd | Wholesale & retail | 2019 |
| Tuckers Independent Trading Ltd | Administrative & support | 2009 |
| Tudor Park Residents (Management Company) Limited | Other services | 2024 |
| Tuff Sports (UK) Ltd | Wholesale & retail | 2003 |
| TUG Transport Ltd | Transport & logistics | 2020 |
| Tulip Journeys Limited | Hospitality | 2021 |
| Tulipwood Properties Limited | Real estate | 2002 |
| Tunhill Limited | Financial services | 2024 |
| Turborocks Limited | Wholesale & retail | 2021 |
| Turkish Barber Taunton Ltd | Other services | 2023 |
| Turmeric Kitchen Taunton Ltd | Hospitality | 2021 |
| Turner Property Management Ltd | Real estate | 2021 |
| Turners Decoratives Ltd | Manufacturing | 2012 |
| TV Ellef Limited | Information & communication | 2006 |
| Tvrp Limited | Financial services | 1999 |
| TW Jones Clinical Imaging Limited | Health & social care | 2016 |
| TW Protection Services Ltd | Administrative & support | 2025 |