| TSG Interior Solutions Ltd | Construction | 2019 |
| TSK Nails & Beauty 38 Ltd | Other services | 2026 |
| TSK Nails & Beauty Ltd | Other services | 2021 |
| TSR Martial Arts Ltd | Arts & recreation | 2025 |
| TU Creative Limited | Administrative & support | 2013 |
| Tuckconuk Limited | Professional & scientific | 2013 |
| Tucker Mechanical Services (London) Limited | Professional & scientific | 1997 |
| Tudor Cafe (Sidcup) Limited | Hospitality | 2023 |
| Tudor-Hall Construction Ltd | Real estate | 2025 |
| Tumes Ltd | Construction | 2023 |
| Tunemypiano Limited | Education | 2025 |
| Tunstill Court T M Limited | Administrative & support | 2018 |
| Turbo Pulse Ltd | Wholesale & retail | 2025 |
| Turner and Sons Fibreoptics Ltd | Administrative & support | 2024 |
| Turow Property Services Limited | Construction | 2020 |
| TVT Plumbing & Heating Ltd | Construction | 2021 |
| TW Hospitality Services Ltd | Financial services | 2026 |
| Twelve Cost Management Limited | Professional & scientific | 2026 |
| TWENTY20 Decor Limited | Construction | 2006 |
| TWENTY3 Ventures Ltd | Real estate | 2018 |
| Twilight Taxi Limited | Transport & logistics | 2025 |
| Twins DRY Cleaning (Penge) Limited | Professional & scientific | 2016 |
| Twisted Tech Solutions Limited | Construction | 2018 |
| Twisted Tulip Designs Limited | Wholesale & retail | 2021 |
| Twizzle Limited | Other services | 2014 |
| Two SJK (NT) Ltd | Administrative & support | 2017 |
| Tyava Ltd | Hospitality | 2024 |
| Tydal Engineering Ltd | Construction | 2019 |
| Tydeman Controls Ltd | Construction | 2017 |
| Tyler Consultancy Limited | Administrative & support | 2006 |
| Typhoon Construction Management Limited | Professional & scientific | 2025 |
| Uddin Empire Ltd | Real estate | 2022 |
| UEC Cross Culture Links Limited | Public administration | 2007 |
| Uffizi Hair and Beauty Gallery Limited | Other services | 1996 |
| UG Branding Ltd | Manufacturing | 2020 |
| UIM Services UK Ltd | Financial services | 2023 |
| UK Education in China Limited | Administrative & support | 2017 |
| UK Mental Health Ltd | Professional & scientific | 2013 |
| UK Outdoors Ltd | Wholesale & retail | 2025 |
| UK UNI Path Ltd | Education | 2025 |
| UK Waste Away Ltd | Water & waste | 2025 |
| Uk-China Education, Culture and Business Services Limited | Other services | 1999 |
| UKB (London) Limited | Construction | 2019 |
| Ultimate Dodgeball Academy Limited | Arts & recreation | 2017 |
| Ultimate Industrial Cleaning Ltd | Administrative & support | 2000 |
| Ultra ELC Ltd | Professional & scientific | 2025 |
| Ultradance Ltd | Education | 2025 |
| Ulusoy Properties Ltd | Real estate | 2023 |
| Umansky Technical Services Limited | Professional & scientific | 2013 |
| UNA Concepts Limited | Hospitality | 2025 |
| Unconditional Limited | Wholesale & retail | 2007 |
| Under Control Ltd | Construction | 2010 |
| Undercastle Close Management Company Limited | Households | 2021 |
| Underwoods Carpentry & Joinery Limited | Construction | 2019 |
| UNG Electrical Ltd | Construction | 2026 |
| Unicus Building Consultancy Limited | Administrative & support | 2021 |
| Unique Lifts Limited | Manufacturing | 2015 |
| Unique Smile Center Ltd | Health & social care | 2014 |
| Unit 21 Holdings Limited | Public administration | 2013 |
| Unitec Building Services Ltd | Construction | 2013 |
| Uniwe Limited | Professional & scientific | 2016 |
| Unparagoned Ltd. | Information & communication | 2023 |
| Uplands Estates Ltd. | Real estate | 1990 |
| Uplands Estates SPV Limited | Real estate | 2025 |
| Uplands Property Investments Limited | Real estate | 2000 |
| UPLANDS1929 Ltd | Real estate | 2018 |
| Urban Horizons Ltd | Households | 2025 |
| Urban Service Company Kent Ltd | Manufacturing | 2020 |
| Urban Window Company South Ltd | Construction | 2015 |
| Urim & K Brickwork Limited | Construction | 2016 |
| Urma Ltd | Hospitality | 2022 |
| Usherwood Investments Limited | Real estate | 2020 |
| Usman Babary & Co Ltd | Wholesale & retail | 2025 |
| Utility Management Training Limited | Education | 2024 |
| Utopia Nail Spa Limited | Administrative & support | 2011 |
| V and V Projects Limited | Administrative & support | 2011 |
| V&E Property Management Limited | Professional & scientific | 2022 |
| V3 Hospitality Services Ltd | Hospitality | 2009 |
| Vaibhavi Enterprise Ltd | Real estate | 2020 |
| Vaibhavi Investment Ltd | Real estate | 2026 |
| Valentine Properties South East Ltd | Real estate | 2021 |
| Valethek Ltd | Construction | 2025 |
| Valtaila Tails Ltd | Agriculture & fishing | 2025 |
| Vangelis Solutions Limited | Information & communication | 1998 |
| Vanguard Power Solutions Ltd | Construction | 2025 |
| Vanquish Expert Property Solutions Limited | Construction | 2023 |
| Vanquish Expert Solutions Group Limited | Real estate | 2010 |
| Vapex Technology Batteries Limited | Extraterritorial | 2008 |
| Varc Holdings Limited | Professional & scientific | 2004 |
| Vartia Electrics Ltd | Construction | 2022 |
| Vascost Ltd | Construction | 2024 |
| Vasile Construction Ltd | Construction | 2017 |
| Vata Construction Ltd | Construction | 2017 |
| Vata Properties Ltd | Real estate | 2023 |
| Vaughan Care Ltd | Health & social care | 2026 |
| VC Landscapes London Limited | Administrative & support | 2015 |
| VCL Management Services Limited | Administrative & support | 2012 |
| VDE Data Solutions Limited | Information & communication | 2024 |
| Veenoct Ltd. | Information & communication | 2002 |
| Vehicle & Asset Solutions Ltd | Administrative & support | 2018 |