| Tribal Golf Ltd | Wholesale & retail | 2023 |
| Tribus Ltd | Professional & scientific | 2018 |
| Tricas Civil Engineering Limited | Construction | 2021 |
| Tricas Construction Limited | Professional & scientific | 2017 |
| Tricky Funsters Cards & Toys Limited | Real estate | 1994 |
| Trideck Roofing Contracts Limited | Construction | 2017 |
| Trident Build & Maintain Ltd | Manufacturing | 2024 |
| Trident Electrics Ltd | Construction | 2026 |
| Trident Group Solutions Limited | Professional & scientific | 2021 |
| Trident Hydraulic & Transient Solutions Ltd | Professional & scientific | 2020 |
| Trident Intelligent Solutions Ltd | Information & communication | 2022 |
| Trident International Limited | Extraterritorial | 2025 |
| Trident Solutions Private Limited | Information & communication | 2020 |
| Tridoc Limited | Real estate | 2019 |
| Trifolium Partnership Limited | Agriculture & fishing | 2020 |
| Trigger Time Training Ltd | Other services | 2018 |
| Trigno UK Limited | Information & communication | 2013 |
| Trimax Enterprises Ltd | Information & communication | 2023 |
| Trinain Fintech Solutions Limited | Information & communication | 2021 |
| Tring Gymnastics Ltd | Health & social care | 2022 |
| Trinity Healthcare Group Ltd | Health & social care | 2023 |
| Trinity Healthcare Support UK Limited | Health & social care | 2024 |
| Trinity Housing Group Ltd | Health & social care | 2022 |
| Trinity Locums Limited | Health & social care | 2016 |
| Trinity Systems Limited | Information & communication | 1995 |
| Trinity Tax Ltd | Professional & scientific | 2019 |
| Triniversal Limited | Information & communication | 2014 |
| Trio Supported Living Limited | Extraterritorial | 2025 |
| Trio Supported Living U.K. Limited | Extraterritorial | 2025 |
| Triple 'a' Medical Limited | Health & social care | 2023 |
| Triple a (MK) Limited | Transport & logistics | 2021 |
| Triple a Properties (a & I) Limited | Real estate | 2018 |
| Triple Bite Ltd | Hospitality | 2024 |
| Triple D Property Services Ltd | Real estate | 2024 |
| Triple Diamond Healthcare Limited | Health & social care | 2018 |
| Triple S Investments Limited | Real estate | 2022 |
| Triple Two Development Limited | Wholesale & retail | 2021 |
| Triple White Weddings Ltd | Administrative & support | 2012 |
| Triplerad Ltd | Professional & scientific | 2016 |
| Tripping Outside Limited | Wholesale & retail | 2024 |
| Tripple 'a' Consult Limited | Professional & scientific | 2009 |
| Triread Acquisitions Limited | Extraterritorial | 2016 |
| Triread Developments Limited | Construction | 2011 |
| Trishool Consulting Limited | Information & communication | 2017 |
| Tristan James Group Ltd | Hospitality | 2018 |
| Tristar Continental UK Ltd | Wholesale & retail | 2020 |
| Triton Hydrogen Limited | Manufacturing | 2022 |
| Trivedy Associates Limited | Professional & scientific | 2022 |
| Trivia Services Ltd | Information & communication | 2023 |
| Trixel Group Ltd | Wholesale & retail | 2021 |
| Triztan Limited | Professional & scientific | 2014 |
| Troboll UK Limited | Health & social care | 2015 |
| Troglotech Limited | Manufacturing | 2004 |
| Trojan Tours Limited | Public administration | 2016 |
| Trolley Buggy Ltd | Manufacturing | 2014 |
| Tropica IT Consultancy Ltd | Information & communication | 2022 |
| Tropical Plumbing & Heating Ltd | Construction | 2019 |
| Tropical TAN & Glam Ltd | Other services | 2025 |
| Tropical Touch Ventures Limited | Wholesale & retail | 2020 |
| Trouble Inc Limited | Professional & scientific | 2026 |
| Trowel TEK Limited | Construction | 2025 |
| Truck and Wheel UK Ltd | Transport & logistics | 2020 |
| Truck&Van Trans Limited | Transport & logistics | 2025 |
| Truckeast Holdings Limited | Financial services | 2023 |
| Truckeast Limited | Wholesale & retail | 1992 |
| Truckme Limited | Transport & logistics | 2025 |
| Trucks and Child Safety Limited | Professional & scientific | 1968 |
| Trucore Ltd | Professional & scientific | 2016 |
| Trudie Sutton Ltd | Professional & scientific | 2015 |
| True 2 U Transport Ltd | Transport & logistics | 2024 |
| True Cleaning Solutions Ltd | Administrative & support | 2023 |
| True Divine Limited | Health & social care | 2015 |
| True Exterior Cleaning Ltd | Administrative & support | 2025 |
| True Faith Generation Ltd | Arts & recreation | 2017 |
| True Friends Ltd | Wholesale & retail | 2025 |
| True HQ Limited | Wholesale & retail | 2019 |
| True Peak Outdoors UK Limited | Wholesale & retail | 2025 |
| True Photo Ltd | Professional & scientific | 2016 |
| True Success Pathway Ltd | Wholesale & retail | 2014 |
| True Tax and Accountancy Limited | Professional & scientific | 2012 |
| Truebalance Accountants Ltd | Professional & scientific | 2024 |
| Trueform Events Ltd | Arts & recreation | 2026 |
| Truegrace Management Limited | Professional & scientific | 2026 |
| Truehealth Solutions Ltd | Health & social care | 2025 |
| Truemark Estates Limited | Real estate | 2026 |
| Truenorth Consultancy Services Ltd | Professional & scientific | 2024 |
| Truespec Ltd | Information & communication | 2026 |
| Truetranslation Ltd | Professional & scientific | 2005 |
| Truhinbrothers Joinery Ltd | Construction | 2022 |
| Trulybakes Ltd | Hospitality | 2023 |
| Truman Design and Build Ltd | Construction | 2016 |
| Trura Consulting Limited | Information & communication | 2017 |
| Truslink Services Limited | Real estate | 2020 |
| Trust Design Services Ltd | Information & communication | 2026 |
| Trust Engineering Group TEG Ltd | Professional & scientific | 2022 |
| Trust Fintech Limited | Information & communication | 2025 |
| Trustap UK Ltd | Other services | 2021 |
| Trustarthur UK Ltd | Financial services | 2021 |
| Trustcv Ltd | Information & communication | 2025 |
| Trusted Cars Limited | Transport & logistics | 2013 |