| Tritax Big Box Developments Ltd | Construction | 2018 |
| Tritax Park Gloucester Management Company Limited | Real estate | 2026 |
| Tritax Park Oxford Management Company Ltd | Real estate | 2024 |
| Tritax Park Wigan Management Company Ltd | Real estate | 2022 |
| Tritax Park Wigan UK Ltd | Construction | 2018 |
| Tritax Symmetry (Aston Clinton) Ltd | Construction | 2018 |
| Tritax Symmetry (Barwell) Ltd | Construction | 2018 |
| Tritax Symmetry (Bicester Reid) Ltd | Construction | 2017 |
| Tritax Symmetry (Blyth) Ltd | Construction | 2017 |
| Tritax Symmetry (Darlington) Ltd | Construction | 2017 |
| Tritax Symmetry (Goole) Ltd | Construction | 2017 |
| Tritax Symmetry (Hinckley) Ltd | Construction | 2017 |
| Tritax Symmetry (Kettering) LLP | | 2013 |
| Tritax Symmetry (Lutterworth) LLP | | 2013 |
| Tritax Symmetry (Rugby) Ltd | Construction | 2018 |
| Tritax Symmetry Biggleswade Land Ltd | Construction | 2021 |
| Tritax Symmetry Development (Biggleswade) UK Ltd | Construction | 2017 |
| Tritax Symmetry Development (Blyth) UK Ltd | Construction | 2017 |
| Tritax Symmetry Merseyside Land Ltd | Construction | 2022 |
| Triumph Razoredge Owners Club Limited | Other services | 1994 |
| Triumph SPV Ltd | Real estate | 2025 |
| Trivlogic UK Ltd | Information & communication | 2024 |
| Trixie UK Pet Products Limited | Wholesale & retail | 2021 |
| TRL Estate Services Limited | Construction | 2024 |
| Trochetia Travel Limited | Hospitality | 2022 |
| Trofim Ltd | Transport & logistics | 2021 |
| Trojan Cars Limited | Manufacturing | 2025 |
| Trojan Logistics Ltd | Transport & logistics | 2014 |
| Tronify Ltd | Wholesale & retail | 2025 |
| Troonvale Scientific Limited | Manufacturing | 2002 |
| Tropical One Limited | Wholesale & retail | 2020 |
| Trout Transport Limited | Transport & logistics | 2015 |
| Troutbeck Limited | Extraterritorial | 2022 |
| Trowell Bookkeeping and Accounts Ltd | Professional & scientific | 2024 |
| Troy (CL) Limited | Extraterritorial | 2007 |
| TRS PLC Ltd | Manufacturing | 2020 |
| Trss Limited | Manufacturing | 2002 |
| TRU Patriot Ltd | Wholesale & retail | 2026 |
| Truck Buddies Ltd | Information & communication | 2025 |
| Truck Motor Centre Ltd | Transport & logistics | 2019 |
| Truck Pro and Van Accessories Ltd | Wholesale & retail | 2022 |
| Truckbnb Limited | Professional & scientific | 2018 |
| Trucked Ltd | Wholesale & retail | 2026 |
| Truckfile Limited | Information & communication | 2006 |
| Truckntrendz.Com Ltd | Other services | 2024 |
| Truckroute Ltd | Transport & logistics | 2025 |
| Trucksafe Limited | Transport & logistics | 2018 |
| Trucktastic Limited | Transport & logistics | 2022 |
| True Beauty (LB) Limited | Other services | 2014 |
| True Circle Limited | Information & communication | 2009 |
| True Credentials Ltd | Administrative & support | 2015 |
| True North Learning & Consulting Limited | Professional & scientific | 2025 |
| True North Trade and Investment Limited | Professional & scientific | 2017 |
| True Space Solutions Ltd | Manufacturing | 2026 |
| True YOU CBT Ltd | Health & social care | 2025 |
| Trueast Limited | Transport & logistics | 2025 |
| Truebeam Ltd | Construction | 2025 |
| Truebrick Ltd | Professional & scientific | 2026 |
| Truehaul Solutions Ltd | Wholesale & retail | 2024 |
| Trueroute Ltd | Transport & logistics | 2026 |
| Truffle Butter Co Ltd | Wholesale & retail | 2024 |
| Trufreight Limited | Transport & logistics | 2018 |
| Trumans Homes Ltd | Real estate | 2024 |
| Trumonix Limited | Professional & scientific | 2012 |
| Trunorft Limited | Professional & scientific | 2022 |
| Trust Transport Ltd | Transport & logistics | 2025 |
| Trusted Help Ltd | Health & social care | 2020 |
| Trusted Psychics Limited | Administrative & support | 2022 |
| Trusted Transport Limited | Transport & logistics | 2020 |
| Trustus Plumbing & Heating Services Ltd | Construction | 2013 |
| Trutalk Limited | Information & communication | 2009 |
| Truva Grill Ltd | Hospitality | 2024 |
| Trydan Electrical Limited | Construction | 2022 |
| Tryple a Ltd | Transport & logistics | 2024 |
| TS Digital Marketing Ltd | Professional & scientific | 2023 |
| TS Joyner Ltd | Health & social care | 2025 |
| TS Land (Sturton) Limited | Real estate | 2021 |
| TS Procurement Services Limited | Administrative & support | 2016 |
| TS Waweru KE Ltd | Real estate | 2025 |
| Tsat Ltd | Transport & logistics | 2021 |
| TSC Electrical Ltd | Construction | 2019 |
| Tsekvest Limited | Financial services | 2024 |
| Tshokwane Investments Limited | Real estate | 2004 |
| Tsinyk Transport Ltd | Wholesale & retail | 2023 |
| Tsk@K Ltd | Construction | 2016 |
| TSL Print Solutions Limited | Manufacturing | 2014 |
| TSM14 Holdings Limited | Arts & recreation | 2026 |
| TSP Restaurant Company Limited | Hospitality | 2014 |
| TST Courier Ltd | Transport & logistics | 2025 |
| Tsunami MMA Limited | Arts & recreation | 2025 |
| Tsworks Technologies UK Ltd | Information & communication | 2022 |
| TT Autos Ltd | Wholesale & retail | 2013 |
| TT Consulting Solutions Limited | Information & communication | 2025 |
| TT Drainage Ltd | Construction | 2023 |
| TT50 Limited | Wholesale & retail | 2010 |
| TTC Comms Ltd | Information & communication | 2022 |
| TTC Property Ltd | Real estate | 2022 |
| TTE Construction Ltd | Construction | 2024 |
| TTL Groundwork Ltd | Construction | 2020 |
| TTM Services Ltd | Health & social care | 2026 |