| Truerootsyoga Ltd | Health & social care | 2026 |
| Trust Networks Ltd | Information & communication | 2005 |
| Trust UK Properties Limited | Construction | 2022 |
| Trusted Compliance Ltd | Wholesale & retail | 2026 |
| Trusted Home Caring Ltd | Health & social care | 2025 |
| Trusted Logistics Ltd | Transport & logistics | 2023 |
| Trustline Healthcare Ltd | Health & social care | 2026 |
| Trustoak Services Limited | Professional & scientific | 2002 |
| Truvig Ltd | Professional & scientific | 2023 |
| TRY Construction Limited | Construction | 1986 |
| TRY Plant Limited | Wholesale & retail | 1972 |
| Tsds Holdings Ltd | Administrative & support | 2023 |
| Tsianos Engineering Limited | Professional & scientific | 2013 |
| TSK1 Ltd | Real estate | 2019 |
| Tstf Transport Limited | Transport & logistics | 2016 |
| TT Beverages Ltd | Wholesale & retail | 2026 |
| TTP Capital Limited | Information & communication | 2016 |
| TU & Co (Holdings) Limited | Real estate | 2022 |
| TU Constructions Limited | Construction | 2025 |
| TU Real Estate Limited | Real estate | 2022 |
| Tudor House (Ponders END) Management Company Limited | Households | 1995 |
| Tudor Mill Management Company Limited | Real estate | 1985 |
| Tuff Explorers Limited | Health & social care | 2025 |
| Tulipa Care Homes Limited | Administrative & support | 2025 |
| Tully Designs Ltd | Professional & scientific | 2013 |
| Turbodrive Cars Ltd | Wholesale & retail | 2024 |
| TURN1 Automotive Ltd | Wholesale & retail | 2020 |
| Turner Jomas & Associates (TJA) Limited | Construction | 2011 |
| Turnkey Software Solutions Ltd. | Information & communication | 2013 |
| Turnstone Control Systems Limited | Construction | 2019 |
| Tutoree Limited | Education | 2023 |
| TVS Distribution Ltd | Transport & logistics | 2024 |
| TW Personal Training Limited | Health & social care | 2014 |
| Twelve Ginger Investments Ltd | Professional & scientific | 2018 |
| Twickenham Green (Bakers Mews) Management Company Limited | Households | 2024 |
| Twickenham Green Square (Twickenham) Management Limited | Households | 2000 |
| Twickenham Reach LLP | | 2024 |
| Twigs & Flower Co. Ltd | Professional & scientific | 2020 |
| Twin-Associates Design Ltd | Professional & scientific | 2024 |
| Twinz Detailz Ltd | Wholesale & retail | 2026 |
| TWM Consultancy Limited | Professional & scientific | 2023 |
| Two Jacks Ltd | Information & communication | 2013 |
| Two Spoons Coffee Ltd | Hospitality | 2023 |
| Two Teaspoons Ltd | Hospitality | 2017 |
| Twyford Holdings Limited | Real estate | 2017 |
| TX Construction Solutions Ltd | Extraterritorial | 2020 |
| TXB Services Ltd | Manufacturing | 2026 |
| TY Clinical Services Ltd | Health & social care | 2025 |
| TY Nant Homes Ltd | Construction | 2026 |
| Tyaani Jewels Ltd | Wholesale & retail | 2025 |
| Tyburnia Partners Limited | Administrative & support | 2022 |
| Tyce Autos Ltd | Professional & scientific | 2018 |
| Tyche Seventy Seven Limited | Real estate | 2020 |
| Tyler Morgan IT Solutions Limited | Administrative & support | 2015 |
| Typhoon 8 Ltd | Administrative & support | 2015 |
| Tyre Giant Hartlepool Ltd | Wholesale & retail | 2017 |
| Tyre Place Limited | Wholesale & retail | 2018 |
| Tyres & Mechanics Ltd | Wholesale & retail | 2023 |
| U 2DAY Holdings Ltd | Wholesale & retail | 2024 |
| U G Food (U.K) Ltd | Manufacturing | 2001 |
| U Value Insulation Limited | Wholesale & retail | 2012 |
| U&P Logistic Ltd | Wholesale & retail | 2018 |
| U.K. Haulage Limited | Information & communication | 1991 |
| U:Mi Drinks Ltd | Wholesale & retail | 2023 |
| UAK Services Ltd | Other services | 2025 |
| UB Best Solutions Limited | Real estate | 2025 |
| UB Brentford Ltd | Hospitality | 2026 |
| UB1 Properties Limited | Real estate | 2023 |
| UB4 Air Systems Ltd | Construction | 2021 |
| UC Inns Ltd | Hospitality | 2017 |
| UCT Training Limited | Professional & scientific | 2025 |
| UD Alnad Ltd | Information & communication | 2012 |
| Udane Limited | Professional & scientific | 2012 |
| Uddin Investment Ltd | Real estate | 2025 |
| Uddine Limited | Transport & logistics | 2019 |
| Udentify Limited | Information & communication | 2020 |
| UFS Holding Ltd | Real estate | 2018 |
| UJM Ltd | Administrative & support | 2024 |
| UK - China Training Limited | Professional & scientific | 2004 |
| UK Autoland Limited | Wholesale & retail | 2024 |
| UK Capital Drainage Limited | Water & waste | 2022 |
| UK Deals Ltd | Wholesale & retail | 2014 |
| UK Direct Deals Ltd | Wholesale & retail | 2026 |
| UK Direct Foods Limited | Wholesale & retail | 2022 |
| UK Electronic Cigarette Limited | Wholesale & retail | 2012 |
| UK Furniture Gallery Ltd | Wholesale & retail | 2024 |
| UK Guandan Club Limited | Wholesale & retail | 2022 |
| UK Hot Sales Limited | Wholesale & retail | 2025 |
| UK IT Geeks Ltd | Information & communication | 2025 |
| UK Marketing and Communication Academy Ltd | Professional & scientific | 2012 |
| UK Parts (Holdings) Ltd | Financial services | 2023 |
| UK Product House Ltd | Wholesale & retail | 2025 |
| UK Rapid Removals Ltd | Transport & logistics | 2025 |
| UK Sarms Ltd | Wholesale & retail | 2025 |
| UK Tuition and Services Limited | Professional & scientific | 2014 |
| Uk-China Travel Limited | Administrative & support | 2014 |
| Uktaxhelp Ltd | Professional & scientific | 2021 |
| Uktaxworld Limited | Administrative & support | 2000 |
| Ulian Limited | Construction | 2016 |
| ULS London Ltd | Extraterritorial | 2020 |