| Travelpoint Systems Limited | | 1993 |
| Treadwell 84 Limited | Administrative & support | 2021 |
| Treadwell Holdings (West Midlands) Limited | Professional & scientific | 2015 |
| Treadwell Property Management Ltd | Real estate | 2018 |
| Trend Studio Limited | Wholesale & retail | 2025 |
| TRI People Fire Safety Consultants Limited | Professional & scientific | 2019 |
| Tribal Clothing Limited | Wholesale & retail | 2022 |
| Tricky Business Limited | Administrative & support | 2009 |
| Trinity Dental Services Limited | Health & social care | 2020 |
| Trinity Housing Ltd | Real estate | 2022 |
| Triple 4 Transport Limited | Transport & logistics | 2003 |
| Triple Glazed Direct (West Midlands) Limited | Wholesale & retail | 2015 |
| Triplechange Limited | Real estate | 1998 |
| Tristan Arthur Architects Limited | Professional & scientific | 2021 |
| Tritech Property Limited | Real estate | 2021 |
| Tritech Solutions Security Fire Electrical Limited | Construction | 2017 |
| Triumph Bham Ltd | Administrative & support | 2023 |
| Trives Consulting Ltd | Professional & scientific | 2021 |
| Trivoltage Ltd | Construction | 2020 |
| Tropatelli Ltd | Manufacturing | 2022 |
| Tropical U.K. Limited | Wholesale & retail | 2023 |
| Truduct Products Limited | Wholesale & retail | 1975 |
| Truecare Network Ltd | Health & social care | 2025 |
| Truelead Coaching Limited | Professional & scientific | 2020 |
| Trulight Renewable Electrics Limited | Manufacturing | 2023 |
| TSD Enterprises Ltd | Extraterritorial | 2024 |
| Tsst Solutions Ltd | Information & communication | 2017 |
| Ttuf Ltd | Real estate | 2021 |
| Tuesday Consultancy Limited | Real estate | 2021 |
| Tulleys Print Ltd | Manufacturing | 2003 |
| Turkish Baeber Windmill Ltd | Other services | 2022 |
| Turnholly Ltd | Arts & recreation | 2005 |
| Turonyx Ltd | Wholesale & retail | 2024 |
| Tuthill Special Projects Limited | Wholesale & retail | 2020 |
| Tuxedo Blue Ltd | Hospitality | 2023 |
| TWENTY11 Developments Limited | Construction | 2022 |
| TWF Enterprises Limited | Other services | 2017 |
| Twin Shore Studio Limited | Information & communication | 2025 |
| Twin Town Performance Ltd | Wholesale & retail | 2023 |
| TWM DIE Tools Limited | Manufacturing | 2010 |
| Two K (Electrical Contractors) Limited | Construction | 2001 |
| TWS Mechanical Ltd | Construction | 2007 |
| Twyning Stores Limited | Wholesale & retail | 2018 |
| Tyduct Ltd | Construction | 2025 |
| TYR Transport Consultancy Ltd | Transport & logistics | 2020 |
| Tyre Bay Supplies Limited | Wholesale & retail | 2013 |
| UBH Fruit Deli UK Limited | Wholesale & retail | 2023 |
| Ublo Distribution Ltd | Administrative & support | 2013 |
| Ublo UK Limited | Wholesale & retail | 2010 |
| UDZ Traffic Ltd | Construction | 2021 |
| Ueaz Holdings Ltd | Financial services | 2021 |
| UK 1 Events Ltd | Administrative & support | 2025 |
| UK Dental Laboratories Ltd | Manufacturing | 2006 |
| UK Environmental Services Group Ltd | Other services | 2023 |
| UK Labels (Holdings) Limited | Administrative & support | 2002 |
| UK Midland Supplies Ltd | Wholesale & retail | 2025 |
| UK Number 1 Cars Limited | Wholesale & retail | 2026 |
| UK S Futures CIC | Education | 2022 |
| Ukcutter Ltd | Wholesale & retail | 2020 |
| Uksell Ltd | Wholesale & retail | 2022 |
| Ultimate Dance Championships Ltd | Arts & recreation | 2023 |
| Ultimate Worktops Limited | Manufacturing | 2019 |
| Ultra Vapour (Halesowen) Limited | Wholesale & retail | 2017 |
| Ultra Vapour (Kidderminster) Limited | Wholesale & retail | 2017 |
| Ultra Vapour Group Limited | Wholesale & retail | 2017 |
| Ultra Vapour Limited | Wholesale & retail | 2013 |
| Ultra-Mation Holdings Limited | Real estate | 2011 |
| Ultravisage Aesthetics Limited | Health & social care | 2011 |
| Uncommon Developments Limited | Households | 2021 |
| Under Pressure Exteriors Ltd | Administrative & support | 2025 |
| Unigreen Products Limited | Wholesale & retail | 2019 |
| Union Bidco Limited | Financial services | 2022 |
| Union Midco Limited | Financial services | 2022 |
| Unique Care Homes Support Limited | Health & social care | 2010 |
| Unique Project Management Limited | Professional & scientific | 2011 |
| Unit Medic-Aids Limited | Wholesale & retail | 1978 |
| United Industrial Converters Limited | Manufacturing | 1998 |
| United Industrial Packaging Limited | Manufacturing | 2017 |
| United Slitting Services Limited | Professional & scientific | 2000 |
| Unity Housing Estate Limited | Real estate | 2025 |
| Universal Beers Ltd | Wholesale & retail | 2010 |
| Universal PUB Group Ltd | Hospitality | 2022 |
| Universal Solutions Trading Limited | Wholesale & retail | 2011 |
| Uplands Partnership Limited | Real estate | 2024 |
| Uplink-It Networks Ltd | Information & communication | 2021 |
| Upper Southwood Limited | Agriculture & fishing | 2022 |
| Upward Care Limited | Health & social care | 2010 |
| Upward Enterprises Limited | Professional & scientific | 2014 |
| Upward Retail Limited | Real estate | 2016 |
| Urban Advisory Ltd | Real estate | 2023 |
| Urban Cactus Co Ltd | Agriculture & fishing | 2026 |
| Urban Vision Real Estate Limited | Real estate | 2020 |
| Urban Willow Ltd | Real estate | 2026 |
| Urwa Logistics Ltd | Wholesale & retail | 2026 |
| USS Limited | Manufacturing | 2000 |
| UV (Harrow 1) Limited | Real estate | 2024 |
| UV (Uxbridge 1) Limited | Real estate | 2025 |
| Uvanted Ltd | Health & social care | 2022 |
| UVE Doble Ltd | Construction | 2022 |
| UXL Foods Ltd | Wholesale & retail | 2023 |