| Tvfs Property Limited | Real estate | 2023 |
| TW Bespoke Limited | Construction | 2019 |
| TW Electrical Services Ltd | Construction | 2020 |
| TW Health Ltd | Health & social care | 2010 |
| TW Signs Limited | Manufacturing | 2012 |
| TW15 Tax Accountant Ltd | Professional & scientific | 2026 |
| Twanamedical Ltd | Health & social care | 2008 |
| Twenty Four Seventy One Ltd | Administrative & support | 2020 |
| Twigge Roofing Limited | Construction | 2023 |
| Twin Oaks Solar Farm Limited | Energy | 2015 |
| Twisleton Court Management Company Limited | Households | 1994 |
| Twist & Loop Limited | Wholesale & retail | 2015 |
| Twist & Loop Properties Ltd | Real estate | 2021 |
| TWL Structures Ltd | Construction | 2021 |
| Two Birds Properties Ltd | Real estate | 2015 |
| Two Lords Court Limited | Real estate | 2019 |
| Two One Trading Limited | Manufacturing | 2024 |
| TWW Yacht Management Ltd | Professional & scientific | 2017 |
| Twysden Court Residents Company Limited | Extraterritorial | 2003 |
| Twyssenden Manor Estate Limited | Agriculture & fishing | 2024 |
| TX Consultancy Limited | Professional & scientific | 2021 |
| Typagrophy Ltd | Other services | 2022 |
| Type Draw Ltd | Professional & scientific | 2018 |
| Tyson Foods Group Limited | Financial services | 2002 |
| Tyson Foods Product Solutions Ltd | Wholesale & retail | 2014 |
| Tyson Foods Products Limited | Wholesale & retail | 1989 |
| Tyson Foods Restaurant Solutions Ltd | Wholesale & retail | 2014 |
| Tyson Foods UK Holding Ltd | Financial services | 2015 |
| Tyson Foods UK Ltd | Wholesale & retail | 2005 |
| Tyson Retail Limited | Hospitality | 2014 |
| Tysum Properties Limited | Real estate | 2018 |
| Tyway Limited | Professional & scientific | 2025 |
| U-Neek International Ltd | Construction | 1996 |
| U.K.E. Properties Limited | Real estate | 2003 |
| Uavmotorsport Limited | Wholesale & retail | 2016 |
| UBT Lettings Ltd | Real estate | 2021 |
| UCO Group Limited | Manufacturing | 2023 |
| UDS - Upstream to Downstream Services Limited | Other services | 2023 |
| UFO Candy Ltd | Manufacturing | 2024 |
| Uga-Kent Foods Ltd | Wholesale & retail | 2025 |
| Ugmedix Ltd | Health & social care | 2026 |
| Uhuru International Consulting Limited | Administrative & support | 2010 |
| UK Consulting Engineers Limited | Professional & scientific | 2000 |
| UK Customs Brokers Ltd | Transport & logistics | 2025 |
| UK Demos Ltd | Construction | 2025 |
| UK JBA Investments Ltd | Households | 2022 |
| UK Luxury Ltd | Wholesale & retail | 2015 |
| UK Manor House Ltd | Health & social care | 2025 |
| UK Prestige Properties Ltd | Real estate | 2025 |
| UK Scaffolding (S.E.) Limited | Construction | 2014 |
| UK Truck & Van Sales Ltd | Wholesale & retail | 2026 |
| UK Will Safe Ltd | Administrative & support | 2017 |
| Ukathmandu Limited | Wholesale & retail | 2024 |
| Ukdividendstocks.Com Ltd | Information & communication | 2012 |
| Ukmc Prestige Auto Services Ltd | Wholesale & retail | 2021 |
| Ukraine Critical Minerals Limited | Mining & quarrying | 2022 |
| Ukrbud 777 Limited | Construction | 2026 |
| Ukremontauto Ltd | Wholesale & retail | 2025 |
| Ukven Ltd | Administrative & support | 2010 |
| Ultima Care and Nursing Limited | Health & social care | 2023 |
| Ultima Care Skills Academy Limited | Education | 2024 |
| Ultimate Solution Properties Limited | Construction | 2007 |
| Ultrafox Software Ltd | Information & communication | 2012 |
| Ultratone Bodyshapers Limited | Extraterritorial | 1979 |
| Ultratone Scientific Instruments Limited | Manufacturing | 1977 |
| Umbrellabird Solutions Ltd | Professional & scientific | 2014 |
| Umedica Laboratories UK Ltd | Manufacturing | 2024 |
| Unconventional Business Ltd | Other services | 2025 |
| Underdown Landscapes Limited | Administrative & support | 2024 |
| Understudios, Ltd | Wholesale & retail | 2026 |
| Ungerer Limited | Manufacturing | 1959 |
| Unibee Accident Repair Ltd | Wholesale & retail | 2020 |
| Unicorn PUB Marden Limited | Hospitality | 2019 |
| Unify Consulting Ltd | Professional & scientific | 2020 |
| Unikrew Production Limited | Professional & scientific | 2019 |
| Unimo Technology Ltd | Information & communication | 2026 |
| Unique Design London Limited | Construction | 2021 |
| Unique Resin Surfaces Limited | Construction | 2020 |
| Unique Venues of London Limited | Other services | 1998 |
| Unique Wild Wood Furniture Limited | Manufacturing | 2024 |
| Uniquely Blessed Limited | Health & social care | 2024 |
| Unit 14 Victory Park Solent Management Company Limited | Households | 2007 |
| Unit 902 Limited | Hospitality | 2021 |
| Unite Ashford C.I.C. | Health & social care | 2024 |
| United Capital Projects Limited | Information & communication | 2018 |
| United Frontier Media and Management Limited | Information & communication | 2011 |
| United Goan Friends UK Ltd | Health & social care | 2022 |
| United Premier Consultancy Services Limited | Professional & scientific | 2018 |
| United Premier Group Limited | Financial services | 2022 |
| United Premier Limited | Financial services | 2022 |
| United Premier Trading Limited | Wholesale & retail | 2022 |
| United Support CIC | Other services | 2020 |
| United Tax Refunds Limited | Professional & scientific | 2017 |
| Universal Grace Film Feminine Limited | Extraterritorial | 2017 |
| Universal Grace Films Ltd | Extraterritorial | 2010 |
| Unlimited Auto Care Ltd | Administrative & support | 2018 |
| Unstoppable Cards Limited | Wholesale & retail | 2011 |
| Unstoppable Girls CIC | Health & social care | 2022 |
| Unstoppable Mindset Limited | Health & social care | 2017 |
| Uphill Farming Ltd | Agriculture & fishing | 2021 |