| THE Red Tile Inn Limited | Hospitality | 2015 |
| THE Reiki Register Ltd | Health & social care | 2025 |
| THE Roman Bath Mixed Food Company Ltd | Hospitality | 2024 |
| THE Scientific Margin Ltd | Information & communication | 2026 |
| THE Shallows Property Management Limited | Real estate | 2008 |
| THE Smeeth Property Group Limited | Real estate | 2026 |
| THE Social BEE Limited | Information & communication | 2022 |
| THE Somerset County Federation of Women's Institutes | Other services | 1993 |
| THE Somerset Plumbing and Heating Company Limited | Construction | 2025 |
| THE Somerset School of Hypnotherapy Limited | Health & social care | 2014 |
| THE Somerset Willow Company Limited | Manufacturing | 2005 |
| THE Spotty Dog Collection Limited | Professional & scientific | 1999 |
| THE Sustainability Collective LLP | | 2021 |
| THE Taunton Comedy Club Limited | Arts & recreation | 2021 |
| THE Taunton Roast Company C.I.C. | Hospitality | 2021 |
| THE Trails Trust | Administrative & support | 1998 |
| THE Tudor Hotel & Restaurant Limited | Hospitality | 2007 |
| THE Village Bakery (Cannington) Ltd | Wholesale & retail | 2005 |
| THE Welding Supplier Limited | Manufacturing | 2013 |
| THE Welding Test Centre Ltd | Professional & scientific | 2024 |
| THE Wendy House Bar Ltd | Hospitality | 2022 |
| THE West Quay Residents Association (Bridgwater) Limited | Hospitality | 1990 |
| THE Willows (Ashburton) Limited | Real estate | 2007 |
| THE Wobblebox Limited | Information & communication | 2022 |
| THE WX Holdings Co Ltd | Financial services | 2024 |
| Theawardscompany Ltd | Wholesale & retail | 2019 |
| Thedigitalcogs (SW) Ltd | Information & communication | 2022 |
| THEOS7 Ltd | Construction | 2015 |
| Thermodynamic Reprocessing Limited | Extraterritorial | 2015 |
| Thermotool Engineering Limited | Manufacturing | 2014 |
| Thesolutionsgroup Ltd | Construction | 2019 |
| Things I Like Ltd | Wholesale & retail | 2014 |
| Thinh Luong Ltd | Real estate | 2016 |
| Thomas Botton's Funfairs Ltd | Arts & recreation | 2024 |
| Thompson Brothers Limited | Real estate | 1904 |
| Thompson's Plumbing & Heating Limited | Construction | 2023 |
| Thorne Farm Racing Limited | Arts & recreation | 2012 |
| Thorner Developments Ltd | Construction | 2015 |
| Those Rodds Limited | Agriculture & fishing | 2021 |
| Threat Reduction Ltd | Professional & scientific | 2015 |
| Three Locations Limited | Real estate | 2003 |
| THR££ of a Kind Ltd | Extraterritorial | 2023 |
| Tier Zero Consultants Limited | Professional & scientific | 2023 |
| Tiffany Crosara Ltd | Other services | 2017 |
| Tigtech Limited | Professional & scientific | 2000 |
| Tiina Bjork Limited | Information & communication | 2023 |
| TIM Hansford Transport Limited | Transport & logistics | 2000 |
| Timark Construction Ltd | Construction | 2021 |
| Timber Solutions UK Limited | Manufacturing | 2009 |
| Timehaste Limited | Financial services | 1990 |
| Timeless Images Limited | Professional & scientific | 2012 |
| Tindoe Ltd | Construction | 2016 |
| Tiny Feet Films Limited | Information & communication | 1987 |
| Tip-Top Petcare Limited | Agriculture & fishing | 2007 |
| Titan Fist Ltd | Wholesale & retail | 2024 |
| Tiverstone Property Ltd | Real estate | 2026 |
| Tiverton Court Management Company Limited | Households | 2006 |
| TJ Burbidge Developments Limited | Construction | 2018 |
| TJP Safety Ltd | Construction | 2024 |
| TLS Training Services Limited | Administrative & support | 2009 |
| TMB Accounting Services Limited | Professional & scientific | 2024 |
| TMB Patterns Limited | Manufacturing | 1984 |
| TMC Inspection Services Ltd | Professional & scientific | 2023 |
| TMS Fashion Ltd | Wholesale & retail | 2026 |
| TMS Integrated Ltd | Construction | 2024 |
| TNR Property Developments Ltd | Construction | 2017 |
| Tolcher Building & Design Ltd | Professional & scientific | 2019 |
| TOM Nutt and SON Limited | Transport & logistics | 2020 |
| Tomohawk Consulting Ltd | Professional & scientific | 2024 |
| Tony Gunning, Electrical and Technical Services Ltd. | Construction | 2023 |
| Top Branch Tree and Garden Services Limited | Administrative & support | 2025 |
| Top Detail Carpentry Ltd | Manufacturing | 2025 |
| Torvean Limited | Real estate | 1978 |
| Total Care (South West) Limited | Health & social care | 2013 |
| Total CNC Ltd | Professional & scientific | 2023 |
| Total Pipework Installations Limited | Construction | 2009 |
| Total Process Systems Ltd | Professional & scientific | 2026 |
| Total Property Services LLP | | 2024 |
| Tottenham Offices & Houses Limited | Financial services | 1999 |
| Tower Options Limited | Professional & scientific | 1995 |
| Town & Country Storage Limited | Administrative & support | 2016 |
| Tracey ANN Cummins Limited | Extraterritorial | 2023 |
| Tramar Developments Limited | Hospitality | 2014 |
| TRANS4CARS Limited | Transport & logistics | 2022 |
| Transcontinental Steel Trading Limited | Wholesale & retail | 2001 |
| Transdel Limited | Transport & logistics | 2025 |
| Travel Chums Ltd | Administrative & support | 2024 |
| Travel Elite Limited | Administrative & support | 2012 |
| Travel Platino Limited | Administrative & support | 2023 |
| TRE3DOM Limited | Construction | 2019 |
| Tree Planters Employment Society | Agriculture & fishing | 2005 |
| Treylith Ltd | Administrative & support | 2025 |
| Trident Fitness (SW) Ltd | Arts & recreation | 2019 |
| Trigger Digital Ltd | Professional & scientific | 2022 |
| Trinketsuk Limited | Wholesale & retail | 2023 |
| Tripconey’S Heavy Plant Welding Ltd | Manufacturing | 2025 |
| Triratna Arts | Arts & recreation | 2012 |
| Triscus Estates Limited | Construction | 2024 |
| Trizo Facilities Limited | Professional & scientific | 2004 |
| Trizo Limited | Manufacturing | 2007 |