| Tree Top Arborists Limited | Administrative & support | 2023 |
| Treetop Cart Ltd | Wholesale & retail | 2023 |
| Trend Bidco Limited | Administrative & support | 2018 |
| Trend Finco Limited | Administrative & support | 2018 |
| Trend Hair Extensions Ltd | Other services | 2014 |
| Trend Midco Limited | Administrative & support | 2018 |
| Trend Networks Limited | Administrative & support | 2018 |
| Trend's Mobile Hair LLP | | 2019 |
| Trendhurst Developments Limited | Construction | 2017 |
| Trendifyuk Ltd | Wholesale & retail | 2024 |
| Trendy Hair Limited | Other services | 2024 |
| Trevalgas Estate Limited | Hospitality | 2000 |
| Trevena Property Management Ltd | Real estate | 2025 |
| Trevor Hunt Ltd | Information & communication | 2021 |
| Trevor Wood Associates Limited | Information & communication | 2017 |
| Trgv Glass Glazing Windows & Doors Limited | Construction | 2018 |
| TRI TEC Limited | Administrative & support | 2016 |
| Triagg Construction Limited | Construction | 2020 |
| Triagg Group Holdings Limited | Financial services | 2022 |
| Triagg Group Trustees Limited | Financial services | 2022 |
| Triagg Residential Lettings Limited | Real estate | 2020 |
| Triagg Services Limited | Real estate | 2021 |
| Triangle Business Park Management Limited | Real estate | 1989 |
| Tribal Living Ltd | Wholesale & retail | 2022 |
| Tribal Pet Foods Limited | Manufacturing | 2012 |
| Tricky Defects Ltd | Information & communication | 2011 |
| Tricore Analysis Solutions Limited | Professional & scientific | 2024 |
| Tricore IT Ltd | Information & communication | 2012 |
| Tricore Property Partners Limited | Real estate | 2025 |
| Triggs Commercial Ltd | Professional & scientific | 2025 |
| Trim Construction Ltd | Construction | 2025 |
| Trimoves Relocation Services Ltd | Transport & logistics | 2025 |
| Trini Solar Limited | Health & social care | 2021 |
| Trinity AD Ltd | Hospitality | 2026 |
| Trinity Basshurst Electrical Ltd | Construction | 2015 |
| Trinity Care Provider Limited | Health & social care | 2020 |
| Trinity Luck Ltd | Wholesale & retail | 2024 |
| Trio Flooring Ltd | Wholesale & retail | 2014 |
| Trio Nine Ltd | Wholesale & retail | 2025 |
| Trio Telecom Limited | Information & communication | 2014 |
| Trioco Ltd | Wholesale & retail | 2025 |
| Tripshrip Limited | Administrative & support | 2024 |
| Triton Technical Consulting Ltd | Information & communication | 2005 |
| Triumphant Solutions Limited | Information & communication | 2007 |
| Triumphdeal Limited | Extraterritorial | 1987 |
| Troggie Limited | Real estate | 2024 |
| Troisieme AGE Limited | Extraterritorial | 2013 |
| Trojan Construction (68 Whitelands Road) Limited | Households | 2017 |
| Trotskee Travel Ltd | Wholesale & retail | 2010 |
| TRU Experience Travel Limited | Administrative & support | 2011 |
| True Colours SLT Limited | Arts & recreation | 2016 |
| True Energy Brokers Limited | Wholesale & retail | 1993 |
| Truebridge EHC Consulting Limited | Professional & scientific | 2025 |
| Trueman Architects Ltd | Professional & scientific | 2010 |
| Truesource Wholesalers Ltd | Wholesale & retail | 2026 |
| Trust House Education Limited | Education | 2017 |
| Trust Love Care Ltd | Health & social care | 2024 |
| Trusted Cleans Limited | Administrative & support | 2026 |
| Trusted Utility Consultants (TUC) Limited | Energy | 2014 |
| TRV High Wycombe Ltd | Wholesale & retail | 2021 |
| TRV High Wycombe Property Ltd | Real estate | 2025 |
| TRW Real Estate Limited | Real estate | 2010 |
| Trytech Limited | Information & communication | 2005 |
| TS Designs Limited | Manufacturing | 1995 |
| TSC Security Limited | Administrative & support | 2011 |
| Tscarpentry Ltd | Construction | 2016 |
| Tsds Group Limited | Construction | 2024 |
| TSH UK Limited | Wholesale & retail | 2009 |
| TSI Instruments Ltd | Manufacturing | 2002 |
| TSI Snowsports Limited | Administrative & support | 2011 |
| Tsion Solutions Limited | Professional & scientific | 2016 |
| TSJ Venture Developments Limited | Real estate | 2024 |
| TSY Construction Ltd | Construction | 2018 |
| TTW Car Club Limited | Administrative & support | 2025 |
| Tudor Mortgage and Finance Limited | Financial services | 2017 |
| Tuffney Performing Arts Ltd | Arts & recreation | 2018 |
| Tuition Company Ltd | Administrative & support | 2005 |
| Tullowmedia Ltd | Information & communication | 2024 |
| Tully Electrics Limited | Construction | 2013 |
| Tunbridge Wells Fire Protection Limited | Wholesale & retail | 1984 |
| Tung Digital Studio Ltd | Information & communication | 2014 |
| Turab Accounting Ltd | Professional & scientific | 2020 |
| Turbanator Logistics Limited | Transport & logistics | 2025 |
| Turbo Acquisitions 10 Bidco Limited | Financial services | 2019 |
| Turbo Acquisitions 10 Topco Limited | Financial services | 2019 |
| Turbolab Ltd | Information & communication | 2011 |
| Turfa Ltd | Wholesale & retail | 2024 |
| Turk Hani Ltd | Hospitality | 2025 |
| Turkiye Furniture London Limited | Wholesale & retail | 2025 |
| Turkuaz Wycombe Limited | Hospitality | 2023 |
| Turners Fish Limited | Hospitality | 2023 |
| Turo Flooring Ltd | Construction | 2025 |
| Turquoise Engineering Ltd | Construction | 2019 |
| Turville Printing Services LLP | | 2012 |
| Tuscan Property Developments Ltd | Real estate | 2021 |
| Tutorflix Ltd | Education | 2026 |
| TVC Cleaning Services Ltd | Administrative & support | 2021 |
| TVF Systems Services Limited | Professional & scientific | 2003 |
| TVS Enterprises Ltd | Real estate | 2008 |
| TW NCA Limited | Extraterritorial | 2005 |