| TW Springboard Limited | Real estate | 2018 |
| TWENTY-2 Cycleworks Ltd | Manufacturing | 2025 |
| Twiford UK Limited | Wholesale & retail | 2025 |
| Twindrive Motors Limited | Wholesale & retail | 2025 |
| Twint Ltd | Arts & recreation | 2012 |
| Two Funky Limited | Wholesale & retail | 2018 |
| Two Seas Hospitality Management Ltd | Hospitality | 2024 |
| Two Seas Hotels Limited | Real estate | 2023 |
| Two Seas Hotels NO2 Limited | Real estate | 2025 |
| Two Worlds Productions Limited | Administrative & support | 2018 |
| TWP Nutrition EU Limited | Wholesale & retail | 2023 |
| Twyman Regent Limited | Extraterritorial | 2013 |
| TY Consulting Services Limited | Information & communication | 2015 |
| TY Property Management Ltd | Construction | 2022 |
| Tyrela Home Support Ltd | Public administration | 2021 |
| Tyres Anywhere Ltd | Wholesale & retail | 2022 |
| Tyreteam Limited | Wholesale & retail | 1999 |
| U OK Ltd | Wholesale & retail | 2023 |
| Uaaww Ltd | Other services | 2017 |
| Uchauffeurs Ltd | Transport & logistics | 2024 |
| UK Auto Centre Limited | Wholesale & retail | 2013 |
| UK Cars (High Wycombe) Limited | Wholesale & retail | 2009 |
| UK Cars Chesham Ltd | Wholesale & retail | 2021 |
| UK Consultant Group Ltd | Professional & scientific | 2023 |
| UK Ecommerce Emporium Limited | Wholesale & retail | 2025 |
| UK GKG Ltd | Wholesale & retail | 2021 |
| UK Luxury Rides Ltd | Transport & logistics | 2025 |
| UK Mats Limited | Administrative & support | 2000 |
| UK Minibus Travel Limited | Transport & logistics | 2016 |
| UK MOT & Auto Centre (High Wycombe) Ltd | Wholesale & retail | 2021 |
| UK Motorcycle Hire Ltd | Administrative & support | 2025 |
| UK Parts Ltd | Wholesale & retail | 2026 |
| UK Properties (H.W) Ltd | Households | 2018 |
| UK Relocation Limited | Administrative & support | 2017 |
| UK School of Framing Limited | Professional & scientific | 2007 |
| UK Solid MIX Concrete Ltd | Manufacturing | 2025 |
| UK Sourcing Limited | Extraterritorial | 2013 |
| UK Steel Centre Corporation Limited | Manufacturing | 2007 |
| UK Talentlink Limited | Administrative & support | 2024 |
| UK Trade International Ltd | Wholesale & retail | 2016 |
| UK Urban Investment Limited | Real estate | 2021 |
| Uk's Car Valeting Ltd | Wholesale & retail | 2011 |
| UK20 Limited | Information & communication | 2000 |
| Ukhottestdeals Limited | Wholesale & retail | 2019 |
| UKK Property Limited | Construction | 2024 |
| UKK1 Property Limited | Construction | 2024 |
| Ultima Car Sales Limited | Wholesale & retail | 2025 |
| Ultimate Banking Limited | Administrative & support | 2008 |
| Ultimate Incentive Limited | Administrative & support | 2000 |
| Ultimate RRS Limited | Administrative & support | 2013 |
| Ultra Health and Nutrition Ltd | Wholesale & retail | 1996 |
| Ultra Krav Maga Limited | Education | 2013 |
| Ultra Sonar Systems Limited | Manufacturing | 2022 |
| Ultraphy Ltd | Professional & scientific | 2015 |
| Ulysses Fire Services Limited | Other services | 2006 |
| Umer’S Autotrader Ltd | Wholesale & retail | 2024 |
| Umrah CAB Services Ltd | Transport & logistics | 2025 |
| Umsa Properties Limited | Real estate | 2023 |
| Unbelievable Saves Ltd | Wholesale & retail | 2022 |
| Unbreakable Waterproofing Limited | Construction | 2015 |
| Unchain Blockchain Ltd | Education | 2023 |
| Uncle Billy Limited | Professional & scientific | 2018 |
| Underground Audio Ltd | Information & communication | 2025 |
| Understory House Ltd | Manufacturing | 2026 |
| UNI Intelligence Ltd | Health & social care | 2024 |
| Unicom Ventures Limited | Professional & scientific | 2014 |
| Unique in Care Ltd | Health & social care | 2011 |
| Unique Integrations Limited | Wholesale & retail | 2011 |
| Unique Security Solutions (UK) Limited | Administrative & support | 2005 |
| Unique.Bold.You. Limited | Professional & scientific | 2024 |
| Unit Administration Limited | Information & communication | 2020 |
| Unit Line Estates Limited | Real estate | 2007 |
| Unit Line Holdings Limited | Professional & scientific | 2000 |
| Unit Line Systems Limited | Construction | 1992 |
| Unita Trading Limited | Wholesale & retail | 2015 |
| United Fusion Limited | Professional & scientific | 2025 |
| United Network (UNS) UK Limited | Information & communication | 2016 |
| United Skills Development Corporation Limited | Education | 2013 |
| United T and C Limited | Manufacturing | 2014 |
| United Trade Division Limited | Real estate | 2006 |
| UNITYCARE4ALL Limited | Public administration | 2026 |
| Universal Pharma Limited | Professional & scientific | 2010 |
| Universal Talent Management Limited | Other services | 2019 |
| Universal Taxis Ltd | Transport & logistics | 2014 |
| UNL Overseas Limited | Real estate | 2023 |
| Unorthodox Entertainment Ltd | Wholesale & retail | 2021 |
| Untraditional Finance Ltd | Other services | 2024 |
| Upcycle Interiors Limited | Construction | 2018 |
| UPH Motors Limited | Wholesale & retail | 2021 |
| Upholstery Trading Limited | Manufacturing | 1998 |
| Uphoria Cars of Marlow Ltd | Transport & logistics | 2025 |
| Uphoria Properties UK Ltd | Real estate | 2024 |
| UPL Building Services Limited | Construction | 2011 |
| Uplevel Learning Ltd | Education | 2026 |
| Uplift Consulting Ltd | Professional & scientific | 2023 |
| Upmarket Restaurants Limited | Hospitality | 1996 |
| Uppal Ventures Ltd | Real estate | 2022 |
| Upper Fifth Street Design Limited | Construction | 2015 |
| Uptown Furnishings Limited | Administrative & support | 2011 |
| Urban Core Investment Ltd | Real estate | 2020 |