| Ungtrans Ltd | Administrative & support | 2024 |
| Unicorn Trails Limited | Administrative & support | 1999 |
| Unified Cacao Ltd | Manufacturing | 2026 |
| Unified Send Ltd | Information & communication | 2026 |
| Unified Supporting Projects CIC | Education | 2023 |
| Unified Taekwon-Do Association (UTA) Ltd | Other services | 2022 |
| Unify Process Magic Ltd | Information & communication | 2021 |
| Union Fast Food Limited | Hospitality | 2017 |
| Union Management Company Limited | Households | 1981 |
| Unionedge Ltd | Professional & scientific | 2025 |
| Unique Boutique Developments Ltd | Real estate | 2019 |
| Unique Designs Limited | Professional & scientific | 2018 |
| Unique Holidays Limited | Hospitality | 2025 |
| Unique Watch Club Limited | Wholesale & retail | 2024 |
| Unique Wide Care Limited | Administrative & support | 2026 |
| Unique Wide Limited | Wholesale & retail | 2026 |
| Unisoftek Limited | Information & communication | 2021 |
| Unitblend Limited | Real estate | 2005 |
| United 5 Star Ltd | Wholesale & retail | 2017 |
| United Holmes Ltd | Households | 2020 |
| United IT Services Ltd | Information & communication | 2023 |
| United Knights Scaffolding Solutions Ltd | Administrative & support | 2017 |
| United Paper Products Limited | Manufacturing | 2001 |
| United Property Holdings Ltd | Real estate | 2020 |
| United Strength Limited | Arts & recreation | 2020 |
| United Travels Bedford Ltd | Administrative & support | 2023 |
| United Wheels UK Limited | Wholesale & retail | 2020 |
| Unitek Systems Limited | Information & communication | 2001 |
| Unitin London Limited | Construction | 2020 |
| Unitrade 2015 Limited | Other services | 2015 |
| Unity Property Group Limited | Real estate | 2018 |
| Unityfirst Ltd | Administrative & support | 2014 |
| Universal Acoustics Limited | Administrative & support | 2008 |
| Universal Bedford Holiday Rentals Limited | Hospitality | 2025 |
| Universal Camping Limited | Hospitality | 2025 |
| Universal Caravan Park Limited | Hospitality | 2025 |
| Universal Commercial Relocation (Holdings) Limited | Transport & logistics | 1978 |
| Universal Commercial Relocation Limited | Transport & logistics | 2009 |
| Universal Health Hub Limited | Health & social care | 2026 |
| Universal Legal Protection Limited | Financial services | 1999 |
| Universal Lodges Limited | Hospitality | 2025 |
| Universal Properties Bedford Ltd | Hospitality | 2025 |
| Universal Smartstay Limited | Real estate | 2024 |
| Universal Studio Rooms Ltd | Real estate | 2025 |
| Universal Vector Trading Ltd | Wholesale & retail | 2023 |
| Unleash Training Limited | Information & communication | 2014 |
| Unlocked Hub Community Interest Company | Health & social care | 2025 |
| Unmistakable Brands Ltd | Professional & scientific | 2025 |
| Unnormal Limited | Professional & scientific | 2023 |
| Unorthodox LDN Limited | Other services | 2023 |
| Unsettled Theatre Limited | Arts & recreation | 2023 |
| Untoben Ltd | Professional & scientific | 2026 |
| Untold Group Limited | Health & social care | 2025 |
| Unus Property Services Ltd | Other services | 2009 |
| UP Accounting Ltd | Professional & scientific | 2019 |
| Up-Stage Arts Ltd | Arts & recreation | 2011 |
| Upfold Limited | Information & communication | 2023 |
| Upfront Database Solutions Limited | Information & communication | 2012 |
| Upper Left Consulting Ltd | Professional & scientific | 2026 |
| Upric Ltd | Wholesale & retail | 2023 |
| Upstream Insight Ltd | Professional & scientific | 2017 |
| Uptrend Enterprises Ltd | Professional & scientific | 2025 |
| Upvc Medics Limited | Construction | 2024 |
| Urban Battlefields Ltd | Arts & recreation | 2019 |
| Urban Cabin Solutions Ltd | Construction | 2026 |
| Urban Elevators Limited | Professional & scientific | 2006 |
| Urban Graphics Ltd | Professional & scientific | 2003 |
| Urban Luxe Property Limited | Real estate | 2022 |
| Urban Revive & Maintenance Limited | Administrative & support | 2017 |
| Urbanite Hair Limited | Other services | 2010 |
| Uridium Limited | Professional & scientific | 2017 |
| USB Advertising Limited | Professional & scientific | 2025 |
| Usvp Management Ltd | Real estate | 2023 |
| Usystems Limited | Manufacturing | 2002 |
| Utac Special Vehicles UK Ltd | Professional & scientific | 2017 |
| Utac UK Holdings Ltd | Professional & scientific | 2015 |
| Utilitrack (Teesside) Ltd | Financial services | 2026 |
| Utilitrack Limited | Energy | 2009 |
| Utility Consultancy Services Limited | Construction | 2022 |
| UTO Ltd | Administrative & support | 2009 |
| Utopia Psychiatry Ltd | Health & social care | 2023 |
| Utrinque Paratus Training Ltd | Other services | 2019 |
| Utsrigging Ltd | Professional & scientific | 2025 |
| UTX Rail Ltd | Other services | 2021 |
| UXS Healthcare Limited | Financial services | 2026 |
| UXS Holdings Limited | Financial services | 2026 |
| Uzed Parts Ltd | Wholesale & retail | 2025 |
| UZI Cutz Ltd | Other services | 2024 |
| Uzocious Software and Networks Consultancy Ltd | Information & communication | 2020 |
| Uzzetech Ltd | Wholesale & retail | 2024 |
| V C Cantaragiu Ltd | Transport & logistics | 2025 |
| V DUB Vans Ltd | Wholesale & retail | 2022 |
| V Group Autos Ltd | Wholesale & retail | 2024 |
| V P Auto Smart Repairs Limited | Construction | 2018 |
| V R Health & Personal Care Ltd | Health & social care | 2019 |
| V S Distribution Ltd | Transport & logistics | 2010 |
| V W Panels Limited | Wholesale & retail | 2010 |
| V&G Wholesale Limited | Wholesale & retail | 2025 |
| V&V Collections Ltd | Transport & logistics | 2025 |
| V-Fix IT Ltd | Manufacturing | 2017 |