| TRT Property Solutions Limited | Real estate | 2025 |
| Trueform Construction Ltd | Construction | 2023 |
| Truemedicine Ltd | Health & social care | 2019 |
| Trueway Advisers Ltd | Professional & scientific | 2025 |
| Truffles and BIO Products Ltd | Agriculture & fishing | 2021 |
| Truly Roasted Limited | Hospitality | 2015 |
| Trusall Ventilation Limited | Construction | 1985 |
| Trust Fabrics Limited | Wholesale & retail | 2016 |
| Trusted Moters Ltd | Wholesale & retail | 2026 |
| Truth Close Protection Security Ltd | Administrative & support | 2025 |
| Truthmoveson Ltd | Wholesale & retail | 2025 |
| Truva Catering Limited | Financial services | 2018 |
| Tryphorm Consultancy Ltd. | Professional & scientific | 2016 |
| TS3D Limited | Information & communication | 2025 |
| Tsaa ATW Limited | Manufacturing | 2025 |
| Tsg.Scents Ltd | Manufacturing | 2025 |
| Tshipamba Global Property Ltd | Real estate | 2025 |
| TSN Nails Limited | Other services | 2026 |
| TSR & SON Ltd | Real estate | 2024 |
| TSR Consultancy Ltd | Administrative & support | 2024 |
| TT Accounts Ltd | Professional & scientific | 2019 |
| TT Avenue Studio Limited | Other services | 2022 |
| TT Nails and Beauty Limited | Other services | 2022 |
| TT Property Services Ltd | Real estate | 2017 |
| Ttcotech Ltd | Wholesale & retail | 2024 |
| TTE Sound Ltd | Information & communication | 2022 |
| Ttech Group Ltd | Administrative & support | 2023 |
| Ttscent Ltd | Wholesale & retail | 2026 |
| TTT Property Services Ltd | Real estate | 2024 |
| Tuan Nguyen Limited | Other services | 2023 |
| Tuan Pham Company Limited | Other services | 2016 |
| Tuan Thuy Limited | Other services | 2016 |
| Tuan&Thuy Limited | Other services | 2023 |
| Tuana Leather Limited | Wholesale & retail | 2020 |
| Tuana Properties Investment Ltd | Real estate | 2022 |
| TUB & Spa Ltd | Extraterritorial | 2023 |
| Tucnurp Ltd | Transport & logistics | 2021 |
| Tudor Food&Wine Ltd | Wholesale & retail | 2024 |
| Tudor Stonework Limited | Construction | 2009 |
| Tuen London Ltd | Administrative & support | 2023 |
| Tuerbel Ltd | Wholesale & retail | 2025 |
| Tuerium Capital LP | | 2015 |
| Tuerium Limited | Hospitality | 2015 |
| Tuerium LP | | 2016 |
| Tufaan Ltd | Hospitality | 2026 |
| Tugs Grooming & Co Limited | Other services | 2025 |
| Tuim Logistics Limited | Transport & logistics | 2023 |
| Tulip Ateliers Ltd | Wholesale & retail | 2025 |
| Tulip Sight Ltd | Real estate | 2020 |
| Tullock Property Services Ltd | Real estate | 2020 |
| Tunica Diagnostics Ltd | Health & social care | 2022 |
| Tuntun Ltd | Wholesale & retail | 2025 |
| Turabi Ltd | Wholesale & retail | 2018 |
| Turbo Expert Ltd | Transport & logistics | 2022 |
| Turcobazaar Limited | Wholesale & retail | 2018 |
| Tureng Solicitors Limited | Professional & scientific | 2025 |
| Turkan Events Ltd | Other services | 2023 |
| Turkic Capital Ltd | Financial services | 2022 |
| Turkish Foods Supplies Limited | Wholesale & retail | 2008 |
| Turkish Online Market Limited | Wholesale & retail | 2024 |
| Turko Adora Ltd | Wholesale & retail | 2024 |
| Turna Decorations Ltd | Construction | 2019 |
| Turna Media Limited | Information & communication | 2020 |
| Turner & Baker Properties Ltd | Real estate | 2021 |
| Turnpike Business Services Limited | Manufacturing | 2008 |
| Turquoise Beauty Clinics Ltd | Other services | 2017 |
| Turvy Tots Ltd | Health & social care | 2021 |
| Tusel Ltd | Wholesale & retail | 2026 |
| Tushi Car Sales Ltd | Wholesale & retail | 2025 |
| Tutor E ALL Ltd | Education | 2024 |
| Tutto Print Ltd | Manufacturing | 2020 |
| Tutun Hani Ltd | Manufacturing | 2013 |
| TV Aerial Group Ltd | Information & communication | 2021 |
| TVD Group Ltd | Construction | 2020 |
| TW Coffee Holdings Ltd | Financial services | 2019 |
| TW Nails Limited | Other services | 2024 |
| TW Services London Limited | Transport & logistics | 2015 |
| TWC Bar Limited | Hospitality | 2019 |
| TWC Cafe Limited | Hospitality | 2019 |
| Twenty One Bees Limited | Households | 2010 |
| Twine Investments Limited | Financial services | 2017 |
| Twins 09 Ltd | Administrative & support | 2019 |
| Twins Fruit & VEG Delivery Ltd | Wholesale & retail | 2025 |
| Twins Movers Limited | Transport & logistics | 2024 |
| TWJ Hales Limited | Professional & scientific | 2020 |
| Two Keys Capital Ltd | Wholesale & retail | 2021 |
| Twoboysthatrock Limited | Hospitality | 2023 |
| Twyford Property Management Company Limited | Households | 1987 |
| Txrx Sound Solutions Limited | Arts & recreation | 2018 |
| TYD Golf Ltd | Manufacturing | 2017 |
| TYD Group Limited | Information & communication | 2024 |
| Tyent International Ltd | Wholesale & retail | 2023 |
| Tyent UK Ltd | Wholesale & retail | 2019 |
| TYM Consulting Limited | Professional & scientific | 2020 |
| TYRE1. Ltd | Wholesale & retail | 2023 |
| Tyrefleet Distribution Ltd | Wholesale & retail | 2025 |
| TZS UK 2013 Ltd | Health & social care | 2025 |
| U & O Ltd | Hospitality | 2026 |
| U&O Construction Ltd | Construction | 2024 |
| U- CEE Solutions Limited | Professional & scientific | 2021 |