| Tsrk Limited | Real estate | 2019 |
| Tsww Holdings Limited | Financial services | 2016 |
| Tubie Pouches Ltd | Wholesale & retail | 2024 |
| Tudor Financial Consulting Ltd | Professional & scientific | 2025 |
| Tulrose UK Limited | Professional & scientific | 2016 |
| Tunbridge Tong Limited | Wholesale & retail | 2024 |
| Turbeau Offshore Power Limited | Manufacturing | 2023 |
| Turbo Fleet Limited | Transport & logistics | 2025 |
| Turgis, Taylor, Armstrong Limited | Real estate | 1979 |
| Turnberry Associates Ltd | Professional & scientific | 2026 |
| Turpins Green Amenities Limited | Households | 1966 |
| Turtle Tots East Berks Limited | Education | 2014 |
| Turtle Tots South Bucks Limited | Education | 2019 |
| Tuscan Pharma Ltd | Wholesale & retail | 2021 |
| TW Tradology Ltd | Wholesale & retail | 2024 |
| Twenty Two Twenty Two Limited | Households | 2023 |
| Twisted Enterprise Ltd | Hospitality | 2023 |
| Two Brothers Tiling Solutions Ltd | Construction | 2024 |
| Two Cranes Property Acquisitions Limited | Real estate | 2026 |
| Two Little Pickles Limited | Wholesale & retail | 2020 |
| Two Plus Trading Ltd | Wholesale & retail | 2021 |
| Two Rivers Services Ltd | Professional & scientific | 2025 |
| Twyman Bradnick Estates Limited | Real estate | 2016 |
| TX Travel Ltd | Transport & logistics | 2026 |
| U I T Limited | Manufacturing | 1992 |
| U.K.Freelancers Limited | Information & communication | 1995 |
| Ubuntu Care Limited | Health & social care | 2025 |
| Ufabrik Ltd | Administrative & support | 2023 |
| UK Bastion Group Ltd | Construction | 2026 |
| UK Creative Covers Ltd | Administrative & support | 2020 |
| UK Expo Limited | Wholesale & retail | 2014 |
| UK Freeze Dried Foods Limited | Manufacturing | 2021 |
| UK Social Club Limited | Information & communication | 2004 |
| UK Software Holdings Limited | Financial services | 2006 |
| UK V8 Co Ltd | Arts & recreation | 2015 |
| UK Writers College Ltd | Education | 2022 |
| Uk&I LA Scheme Limited | Financial services | 1991 |
| UKG Technology Limited | Other services | 1990 |
| Ukolos Limited | Construction | 2023 |
| Ulitron Limited | Information & communication | 2012 |
| Ultra AP Ltd | Real estate | 2017 |
| Ultra Build Construction Limited | Construction | 2016 |
| UMH Management Limited | Professional & scientific | 2024 |
| Umpiring Worldwide Ltd | Arts & recreation | 2025 |
| Umut Kebabs Ltd | Hospitality | 2025 |
| Under Construction Gym Wear Ltd | Wholesale & retail | 2026 |
| Under the Olive Tree Limited | Wholesale & retail | 2018 |
| Uni-Biotech Solutions Ltd | Manufacturing | 2025 |
| Uniglobal Marketing Company Limited | Wholesale & retail | 2022 |
| Uniq Consulting Ltd | Professional & scientific | 2013 |
| Unique Car Wash Ltd | Professional & scientific | 2025 |
| Unique Home Buildings Ltd | Construction | 2021 |
| Uniquely Paint Ltd | Construction | 2024 |
| Uniquo Limited | Wholesale & retail | 2025 |
| Unit 44 LLP | | 2010 |
| Unit Group Limited | Transport & logistics | 2016 |
| United Design & Build Construction Ltd | Construction | 2022 |
| United Sports Group Ltd | Arts & recreation | 2025 |
| United Travel & Tours Limited | Wholesale & retail | 2025 |
| Universal Building Controls Limited | Information & communication | 2012 |
| Universal Emergency and Rescue C.I.C. | Public administration | 2024 |
| Universal Strategic Arts Ltd | Information & communication | 2025 |
| Unltd Dream Company Ltd | Professional & scientific | 2021 |
| UNO Consulting Ltd | Professional & scientific | 2022 |
| UOP International Holdings Limited | Financial services | 2004 |
| UOP Limited | Manufacturing | 1953 |
| UOP Middle East Company Limited | Other services | 1978 |
| UOP Products UK Limited | Other services | 1951 |
| UOP Services Limited | Administrative & support | 1998 |
| Uplifttherapy Ltd | Health & social care | 2024 |
| Upowa Ltd | Construction | 2021 |
| Uptodate Property Solutions Ltd | Construction | 2023 |
| Urban Essence Limited | Wholesale & retail | 2025 |
| Urban GEM Limited | Real estate | 2023 |
| Urban Heaven Limited | Real estate | 2025 |
| Urban Landscape Design and Construction Ltd | Administrative & support | 2015 |
| Urban Moose Limited | Extraterritorial | 2016 |
| Urban Roofing Solutions Ltd | Construction | 2025 |
| Ursa Health Consulting Ltd | Information & communication | 2026 |
| Utility Refund & Reduction Ltd | Extraterritorial | 2012 |
| Utnicki Haulage Ltd | Transport & logistics | 2026 |
| Uvagatron Ltd | Information & communication | 2026 |
| V G International Trading Limited | Wholesale & retail | 2010 |
| V Lash Studio Ltd | Other services | 2023 |
| V-Ready Limited | Agriculture & fishing | 2017 |
| V2V Developments Ltd | Construction | 2026 |
| VAA Distribution Ltd | Transport & logistics | 2020 |
| Vadesings Ltd. | Information & communication | 2016 |
| Valdi Healthcare Services Ltd | Health & social care | 2019 |
| Valentine Courier Limited | Administrative & support | 2019 |
| Valycourier Ltd | Transport & logistics | 2023 |
| Vanguard Recovery Ltd | Transport & logistics | 2025 |
| Vantage Property Group Ltd | Real estate | 2019 |
| Vantrel Holdings Ltd | Extraterritorial | 2025 |
| Variome Ltd | Information & communication | 2026 |
| Vartel Private Limited | Information & communication | 2023 |
| Vaultech Circularity Associates Ltd | Information & communication | 2026 |
| Vbosh Barbers Ltd | Other services | 2024 |
| VC Future Services Ltd | Construction | 2026 |
| VEA Group Limited | Construction | 2021 |