| Trennco Ltd | Wholesale & retail | 2023 |
| Tresoul Ltd | Real estate | 2020 |
| TRI Talent Resourcing Ltd | Professional & scientific | 2018 |
| Tritax Cobham Marlow (Carry) LP | | 2010 |
| Troikanet Limited | Extraterritorial | 2009 |
| Trojan Fencing Ltd | Construction | 2018 |
| Trojan Global Limited | Administrative & support | 2014 |
| Troutsdale Properties Limited | Professional & scientific | 1973 |
| Trowelskillz Ltd | Construction | 2025 |
| True Reflection Coaching Limited | Professional & scientific | 2019 |
| True Reflection Partnership Ltd | Education | 2021 |
| Truloo Event Management Limited | Arts & recreation | 2021 |
| Trust in People Ltd | Administrative & support | 2025 |
| Trusurv Limited | Professional & scientific | 2024 |
| TSL Enterprises Ltd | Administrative & support | 2018 |
| Tufnells Interiors Ltd | Wholesale & retail | 2006 |
| Turbomachinery Controls Limited | Professional & scientific | 2015 |
| Turkeymilk Ltd | Wholesale & retail | 2020 |
| Turner Tennis Limited | Arts & recreation | 2007 |
| Turners Hill Garage Limited | Real estate | 1969 |
| Turners PUB Company Ltd | Extraterritorial | 2019 |
| Turnershill Tree Surgeons Ltd | Agriculture & fishing | 2019 |
| Turning Point Trading Limited | Administrative & support | 2009 |
| Turtle Bay Solutions Ltd | Manufacturing | 2022 |
| Turun UK Ltd | Manufacturing | 1994 |
| Tuscan Noble Consulting Ltd | Information & communication | 2012 |
| Tutus Housing Limited | Real estate | 2019 |
| Tvrtle Ltd | Information & communication | 2024 |
| Twineham Timber Limited | Agriculture & fishing | 2010 |
| Two Hoots Aviation Limited | Professional & scientific | 2015 |
| Tyler’S Island Ltd | Wholesale & retail | 2025 |
| TYM Marketing Ltd | Professional & scientific | 2024 |
| Tærre Ltd | Hospitality | 2023 |
| UBO Holdings Ltd | Financial services | 2015 |
| UBO Limited | Financial services | 2015 |
| UK Padel Association Ltd | Arts & recreation | 2024 |
| UK Risk Consulting Ltd | Professional & scientific | 2019 |
| UK Services & Supplies Limited | Construction | 2009 |
| UK Veterans Gaming C.I.C. | Other services | 2023 |
| Ukoost Ltd | Information & communication | 2022 |
| UKP Consultancy Limited | Real estate | 2009 |
| Ukpips | Other services | 2012 |
| Ultimate Dance Events Limited | Arts & recreation | 2024 |
| Ultracar Limited | Professional & scientific | 2016 |
| Umbrella Promotions Group Limited | Manufacturing | 2006 |
| Umis Consultancy Ltd | Information & communication | 2011 |
| Umoto Limited | Financial services | 2022 |
| Underdog Development Ltd | Information & communication | 2020 |
| Unibloc Hygienic Technologies UK, Ltd | Manufacturing | 1990 |
| Unique 10 Hair Boutique Ltd | Other services | 2022 |
| United Global Innovations Limited | Professional & scientific | 2024 |
| United Swimming Academy Ltd | Arts & recreation | 2021 |
| Universal Quantum Ltd | Manufacturing | 2018 |
| Unquestionable Ltd | Wholesale & retail | 2023 |
| UP Partners LLP | | 2021 |
| UP Venture Capital LLP | | 2022 |
| Upful Media Ltd | Information & communication | 2023 |
| Upholstery Services Ltd | Other services | 2025 |
| Upmass Limited | Wholesale & retail | 2023 |
| Upper Beeding Holdings Limited | Extraterritorial | 2018 |
| Uppercase Solutions Limited | Information & communication | 2024 |
| Uptick Group Limited | Professional & scientific | 2021 |
| Uptick Limited | Professional & scientific | 2018 |
| Upton Residents Company Ltd | Households | 2022 |
| Urban Space Design and Build Limited | Construction | 2024 |
| Urcompliant Limited | Administrative & support | 2009 |
| UTA Fibre Limited | Information & communication | 2012 |
| Utilligence Ltd | Professional & scientific | 2013 |
| V&R Designs Ltd | Professional & scientific | 2017 |
| Vala Group Holdings Ltd | Information & communication | 2019 |
| Vala VC Ltd | Other services | 2020 |
| Valenna Ltd | Construction | 2025 |
| Valenverse Ltd | Manufacturing | 2023 |
| Valid Productions Limited | Arts & recreation | 2008 |
| Valid Worldwide Limited | Professional & scientific | 2001 |
| Valletta Capital Partners Limited | Construction | 2016 |
| Valletta Holdings Ltd | Real estate | 2017 |
| Valoris Advisory Ltd | Professional & scientific | 2026 |
| Van DEN Boomen Limited | Professional & scientific | 1997 |
| Vanderwalt Ltd | Wholesale & retail | 2021 |
| Vanguard Arms Ltd | Wholesale & retail | 2024 |
| Vantech Sussex Limited | Wholesale & retail | 2012 |
| Varsity Projects Limited | Professional & scientific | 2014 |
| Vaya PVT Limited | Real estate | 2017 |
| VC Lending Limited | Financial services | 2019 |
| Vector Solutions UK Ltd | Information & communication | 2012 |
| Vedra Events Limited | Other services | 2016 |
| Vega Executive Search Ltd | Other services | 2024 |
| Vehicle 4 U Limited | Wholesale & retail | 2020 |
| Vel's Properties Limited | Real estate | 2025 |
| Velocent Ltd | Information & communication | 2025 |
| Velodream Limited | Real estate | 2005 |
| Velvet Riot Creative LLP | | 2024 |
| Velvet Rose Fashion Ltd | Wholesale & retail | 2018 |
| Venator Consulting International Limited | Professional & scientific | 2020 |
| Venice Virtual Services Limited | Administrative & support | 2016 |
| Venti Properties Limited | Real estate | 2018 |
| Ventnor RTM Company Limited | Households | 2023 |
| Venture Associates Management Ltd | Professional & scientific | 2025 |
| Veranding Limited | Administrative & support | 2010 |