| THE Stratton Hotel Ltd | Hospitality | 2016 |
| THE Sustainable Pension Company Limited | Professional & scientific | 2009 |
| THE Talland School of Equitation LLP | | 2012 |
| THE Tidy Team Service Ltd | Administrative & support | 2025 |
| THE Tinsmiths (Retail) Limited | Wholesale & retail | 2018 |
| THE Tinsmiths Limited | Wholesale & retail | 2019 |
| THE Tithe Barn Bolton Abbey Ltd | Hospitality | 2018 |
| THE Training Shop Limited | Education | 2011 |
| THE Transport Group Ltd | Transport & logistics | 2026 |
| THE Unfiltered Bride Podcast Limited | Information & communication | 2023 |
| THE Vehicle Body Shop Limited | Wholesale & retail | 2017 |
| THE Vein Clinic Swindon Ltd | Health & social care | 2026 |
| THE Victoria Inn Eastleach Ltd | Hospitality | 2016 |
| THE Village Cafe (Kidlington) Ltd | Administrative & support | 2022 |
| THE Watermark Club Limited | Arts & recreation | 1998 |
| THE Watermark Leisure Group Limited | Extraterritorial | 1998 |
| THE Wild Collection Ltd | Hospitality | 2018 |
| THE Willow Trust | Health & social care | 1989 |
| THE Yellow-Lighted Bookshop Limited | Wholesale & retail | 2007 |
| The-Wild-Olive Ltd | Hospitality | 2023 |
| Thebread GL7 Ltd | Hospitality | 2025 |
| Therese Dolan Strategist Limited | Professional & scientific | 2023 |
| Thermal Ltd | Construction | 2008 |
| Thermequin Ltd | Manufacturing | 2021 |
| Thessaly Lodge Limited | Households | 1984 |
| Think Whole Limited | Professional & scientific | 2014 |
| Thinkalike Limited | Information & communication | 2011 |
| Thinking Decisions Ltd | Professional & scientific | 2008 |
| Thinsliced Limited | Information & communication | 2026 |
| Thirst Link (RGB) Ltd | Administrative & support | 2008 |
| Thirty Two Solutions Ltd | Professional & scientific | 2020 |
| Thomas Brothers Construction Ltd | Construction | 2022 |
| Thomas Dean Architects Limited | Professional & scientific | 2015 |
| Thomas Root Builders Ltd | Construction | 2026 |
| Thomson Services Ltd | Construction | 2021 |
| Thornley Kelham Ltd. | Wholesale & retail | 2008 |
| Thoroughbid Limited | Wholesale & retail | 2020 |
| Thorpe Garden Ltd | Hospitality | 2019 |
| Thovex Limited | Information & communication | 2019 |
| Three Hills Property LLP | | 2009 |
| Tickage Ltd | Agriculture & fishing | 2016 |
| Tidmarsh Environmental Geology Ltd | Professional & scientific | 2020 |
| Tiger Build & Renovate Ltd | Construction | 2024 |
| Tiger Fulfilment Ltd | Administrative & support | 2021 |
| Tiger Systems Ltd | Information & communication | 2016 |
| TIM Jeans Consultancy Limited | Professional & scientific | 2016 |
| Timbic Limited | Manufacturing | 2011 |
| Timbrell Farming Limited | Agriculture & fishing | 2010 |
| Tiny Global Coaching Ltd | Professional & scientific | 2024 |
| TJ Carpentry & Joinery Limited | Construction | 2002 |
| TJ Leigh Services Limited | Professional & scientific | 2023 |
| Toadsmoor Garage Limited | Wholesale & retail | 2000 |
| TOM Beim Limited | Construction | 2024 |
| TOM I'Anson Wines Ltd | Wholesale & retail | 2012 |
| Tootsy Limited | Hospitality | 2022 |
| Top Bins Records Ltd | Information & communication | 2024 |
| Topnotch Roofing & Property Maintenance Ltd | Construction | 2025 |
| Tora Group Ltd | Financial services | 2021 |
| Total Projects Group Ltd | Professional & scientific | 2023 |
| Total Surface Solutions Limited | Construction | 2004 |
| Toto Consulting Ltd | Professional & scientific | 2018 |
| Tower Street Communications Ltd | Professional & scientific | 2024 |
| TPM Cotswold Ltd | Real estate | 2020 |
| Tradewind Advisory Limited | Professional & scientific | 2024 |
| Tragus Group Ltd | Information & communication | 2018 |
| Train 4 Change Limited | Other services | 2000 |
| TRAIN4CHANGE Group Limited | Other services | 2017 |
| Trans-Euro Industries Limited | Transport & logistics | 1992 |
| Transform for Results Ltd | Real estate | 2021 |
| Trap House Court Management Co. Ltd | Real estate | 2007 |
| Trash Planet Ltd | Manufacturing | 2020 |
| Travation Ltd | Professional & scientific | 2024 |
| Travelnam Ltd | Administrative & support | 2023 |
| Treadwave Ltd | Other services | 2019 |
| Trent-Services (Administration) Limited | Financial services | 2004 |
| Tri-Flx Ltd | Manufacturing | 2023 |
| Tribrisant Trading Company Limited | Professional & scientific | 2011 |
| Tributes.Online Limited | Other services | 2025 |
| Tricol Consultancy Limited | Information & communication | 2015 |
| Trifold (Cheltenham) Ltd | Real estate | 2017 |
| Triglyph Property Limited | Real estate | 2023 |
| Tring Financial Management Limited | Professional & scientific | 2005 |
| Triple M Holdings Limited | Financial services | 2024 |
| Trouble-Halt Ltd | Professional & scientific | 2025 |
| Trove Gems Ltd | Wholesale & retail | 2023 |
| True Concept Limited | Extraterritorial | 2019 |
| Trust Data Systems Ltd | Information & communication | 2019 |
| Trust Systems EBT Trustee Limited | Information & communication | 2026 |
| Trust Systems Limited | Information & communication | 2006 |
| TRV Catering Ltd | Hospitality | 2024 |
| Tseare Ltd | Professional & scientific | 2026 |
| TSW (Wholesale) Ltd | Wholesale & retail | 2024 |
| Tucked Limited | Construction | 2025 |
| Tugwell Contracting Agriculture Limited | Agriculture & fishing | 2021 |
| Tugwell Contracting Construction Limited | Administrative & support | 2015 |
| Tugwell Contracting Solar Limited | Professional & scientific | 2021 |
| Turner & Hares Limited | Wholesale & retail | 2018 |
| Turner AI Labs Limited | Information & communication | 2026 |
| Tusker Holdings Limited | Wholesale & retail | 2020 |
| Twenty Something Design Ltd | Professional & scientific | 2026 |