| Top Garage Limited | Administrative & support | 2012 |
| Top Glazing Ltd | Construction | 2019 |
| Top of Many Mountains Ltd | Real estate | 2025 |
| Top Village Pizza Ltd | Hospitality | 2018 |
| Topsham Care Home Holdings Limited | Financial services | 2019 |
| Topsham Care Home Limited | Real estate | 2019 |
| Topsham Care Limited | Health & social care | 2019 |
| Torbury House Limited | Financial services | 2024 |
| Torchmark Limited | Professional & scientific | 2021 |
| Torsa Leisure Limited | Other services | 2023 |
| Torsa Studios Limited | Wholesale & retail | 2016 |
| Tosh United Limited | Health & social care | 2010 |
| Total Body Health Ltd. | Health & social care | 2019 |
| Total Design Solutions Limited | Construction | 2015 |
| Total Electrical Services & Testing Limited | Manufacturing | 1999 |
| Totara Developments Limited | Real estate | 2021 |
| Totara Properties Limited | Real estate | 2021 |
| TP Trades Ltd | Real estate | 2022 |
| Tpanco Limited | Professional & scientific | 2014 |
| Trade for Future Ltd | Professional & scientific | 2022 |
| Trade Porter Limited | Other services | 2024 |
| Trade Square Ltd | Construction | 2023 |
| Traffic Tech U.K Limited | Transport & logistics | 2008 |
| Train United Ltd | Other services | 2020 |
| Training for ALL Limited | Transport & logistics | 2024 |
| Trakz Trade Limited | Construction | 2023 |
| Transit Courier Limited | Transport & logistics | 2025 |
| Tree-Huggers United Ltd | Other services | 2023 |
| Trends to Market International Ltd. | Construction | 2006 |
| Tribute Legacy Limited | Information & communication | 2023 |
| Trickshot Limited | Information & communication | 2022 |
| Tricord Solutions Ltd | Administrative & support | 2020 |
| Trider Ltd | Professional & scientific | 2025 |
| Tridev Holdings Ltd | Real estate | 2025 |
| Trima Investments UK Ltd | Professional & scientific | 2023 |
| Trinity Roofing & Sons Limited | Construction | 2025 |
| Triple Invest Ltd | Real estate | 2023 |
| Tristone Properties Ltd | Real estate | 2023 |
| Troyavi Ltd | Wholesale & retail | 2010 |
| Truvest Capital LLP | | 2023 |
| Ttwvision Ltd | Financial services | 2021 |
| Tuck Tuck UK Ltd | Real estate | 2024 |
| Tudor Project Services Limited | Construction | 2017 |
| Tulleys Ltd | Wholesale & retail | 2010 |
| Tundra Software UK LLP | | 2019 |
| Tuneout Limited | Real estate | 2013 |
| Tuning-Server.Com Ltd | Other services | 2024 |
| Turkfix Limited | Construction | 2026 |
| Turner's Pizza's Limited | Hospitality | 2025 |
| TUV Arabia Ltd | Construction | 2021 |
| TVR Investments Limited | Professional & scientific | 2015 |
| TW20 Residential Ltd | Real estate | 2026 |
| TWA Transport Limited | Transport & logistics | 2009 |
| Twin Industries Agencies Limited | Real estate | 1973 |
| Two Pillars Ltd | Real estate | 2025 |
| Tylogistics Ltd | Transport & logistics | 2008 |
| Typhoon Limited | Wholesale & retail | 1971 |
| U E Onishi Limited | Wholesale & retail | 2012 |
| U Link Car Decor Ltd | Wholesale & retail | 2023 |
| U Link Limited | Transport & logistics | 2011 |
| Uaif.Net Ltd | Other services | 2024 |
| Udden Ltd | Real estate | 2025 |
| UK Capital Property Ltd | Real estate | 2019 |
| UK Hold Limited | Financial services | 2023 |
| UK Liaoning Association | Other services | 2011 |
| UK Property Affairs Ltd | Real estate | 2025 |
| UK Roofing & Building Limited | Construction | 2024 |
| UK Student Services Limited | Education | 2023 |
| UK Thermal Supplies Limited | Construction | 2024 |
| UKB Management Ltd | Professional & scientific | 2024 |
| Ukbeautyque Limited | Wholesale & retail | 2021 |
| Ukcoatingsconsulting Ltd | Professional & scientific | 2017 |
| UKL Advisory Ltd | Professional & scientific | 2025 |
| ULI Kress Limited | Real estate | 2022 |
| Ulwell Beach Huts Limited | Real estate | 2010 |
| UM Orthotics Limited | Wholesale & retail | 2025 |
| Umarell Properties Ltd | Real estate | 2025 |
| Underdown Construction Services Ltd | Construction | 2015 |
| Unica Property Investments Ltd | Real estate | 2024 |
| Unicorn Financial Solutions Limited | Professional & scientific | 1998 |
| Unificloud Limited | Information & communication | 2017 |
| Union Street Management (Kingston) Ltd | Hospitality | 2024 |
| Unique Concepts Design Limited | Construction | 2020 |
| United Property Rentals Ltd | Real estate | 2021 |
| Unity of Sociologists Ltd | Other services | 2025 |
| Universal Electrical Solutions Limited | Other services | 2009 |
| Unlimited Trust Ltd | Real estate | 2022 |
| Unlockd Media Technology Ltd | Information & communication | 2015 |
| Unlocked Media Ltd | Professional & scientific | 2025 |
| Upton Hamlet Land Protection CIC | Professional & scientific | 2026 |
| Urban Wealth Ltd | Real estate | 2020 |
| Ussat Ltd | Other services | 2026 |
| Utility Skills Ltd | Education | 2022 |
| UV Magic Limited | Financial services | 2022 |
| V M Solutions Limited | Administrative & support | 2006 |
| Vagapse Ltd | Professional & scientific | 2022 |
| Vakula Life Ltd | Professional & scientific | 2025 |
| Valentebottaio Property Investments UK Limited | Real estate | 2017 |
| Valldone Ltd | Wholesale & retail | 2023 |
| Value Added Properties Ltd | Real estate | 2022 |