| UK Barber Lounge Limited | Other services | 2015 |
| UK Building Supplies Ltd | Wholesale & retail | 2024 |
| UK Carrom Federation Ltd | Arts & recreation | 2012 |
| UK Distribution Ltd | Administrative & support | 2015 |
| UK Energetic Materials Limited | Manufacturing | 2018 |
| UK Film Industry.Com Limited | Information & communication | 2011 |
| UK Health Consultancy Ltd | Professional & scientific | 2019 |
| UK International Education Center Limited | Education | 2019 |
| UK Lifting Limited | Construction | 2014 |
| UK Postings Limited | Transport & logistics | 2000 |
| UK Puma Defence Limited | Arts & recreation | 2016 |
| UK Santini Limited | Professional & scientific | 2019 |
| UK Security Group Ltd | Administrative & support | 2014 |
| UK Spice Services Ltd | Wholesale & retail | 2025 |
| UK Study Connect Ltd | Education | 2023 |
| UK Tax & Accounting Ltd | Professional & scientific | 2016 |
| UK Telecoms Research Ltd. | Information & communication | 1989 |
| UK Window Wizard Repairs Ltd | Manufacturing | 2024 |
| Ukcc Ltd | Information & communication | 2026 |
| Ukmatrix Real Estate Partners Ltd | Administrative & support | 2013 |
| UKP Digital Limited | Information & communication | 2018 |
| UKP Holdings Ltd | Extraterritorial | 2022 |
| UKP Worldwide Limited | Transport & logistics | 2025 |
| Ulmi Construction Limited | Construction | 2018 |
| Ulrika U.K. Limited | Other services | 2007 |
| Ultimate Tyres Ltd | Wholesale & retail | 2020 |
| Ulysses Research and Advisory Limited | Agriculture & fishing | 2016 |
| UM Estates Ltd | Real estate | 2021 |
| Umbrella Digital Limited | Information & communication | 2020 |
| Umbrella Plumbing and Heating Ltd | Construction | 2019 |
| UNA Vida Consultancy Ltd | Professional & scientific | 2022 |
| Under the Lens VET Consulting Ltd | Professional & scientific | 2022 |
| UNI Enrol Ltd | Education | 2024 |
| Unic Consult Limited | Information & communication | 2021 |
| Uniik Limited | Health & social care | 2022 |
| Union T Limited | Wholesale & retail | 2013 |
| Uniprize Holdings Limited | Administrative & support | 2016 |
| Uniqflow Ltd | Information & communication | 2025 |
| Unique Consultancies Ltd | Administrative & support | 2021 |
| Unique Flooring Supply Limited | Construction | 2013 |
| Unique Infinite-Innovations.Com Ltd | Extraterritorial | 2000 |
| Unique-Admin Ltd | Administrative & support | 2018 |
| Unisoftint Limited | Information & communication | 2018 |
| United Dynamics Limited | Professional & scientific | 2020 |
| United Gymnastics Limited | Arts & recreation | 2025 |
| Unity Lime Products Limited | Manufacturing | 2018 |
| Universal Damp Limited | Construction | 2026 |
| Universal Painters Ltd | Construction | 2023 |
| UP & SRP Investments Limited | Real estate | 2023 |
| Upbeat Minds Ltd | Health & social care | 2023 |
| Upgrade Real Estates Ltd | Real estate | 2023 |
| Upgradeitus Limited | Wholesale & retail | 2018 |
| UPH & GAS Ltd | Construction | 2020 |
| Upon Retail Limited | Wholesale & retail | 2025 |
| Upskill Learning Education Ltd | Education | 2025 |
| URA Thrusters Ltd | Professional & scientific | 2019 |
| Urban Oasis Estates Limited | Households | 2024 |
| Urban Skylights Limited | Construction | 2025 |
| Urban Travel Ltd | Transport & logistics | 2024 |
| Urban Utopia Ltd | Construction | 2026 |
| URI Studio Limited | Manufacturing | 2021 |
| Utility Pros (UK) Limited | Construction | 2012 |
| Utimaco IS UK Limited | Information & communication | 2012 |
| Utmost Life and Pensions Holdings Limited | Professional & scientific | 2017 |
| Utmost Life and Pensions Limited | Financial services | 2017 |
| Utmost Life and Pensions Services Limited | Professional & scientific | 2017 |
| Utmost Properties Ltd | Real estate | 2022 |
| Utmostcare Limited | Administrative & support | 2020 |
| Utopia Coffee Shop Limited | Wholesale & retail | 2017 |
| Uvaa UK Ltd | Real estate | 2025 |
| UVH Ltd | Wholesale & retail | 1999 |
| Uxbridge Accounting Solutions Limited | Professional & scientific | 2010 |
| UZ Visions Ltd | Wholesale & retail | 2025 |
| V N Jewellery Limited | Wholesale & retail | 2013 |
| V O R Facilities Limited | Administrative & support | 2023 |
| V.Robinson & SON Limited | Real estate | 1954 |
| Vaarahii PVT Ltd | Financial services | 2025 |
| Vaat Solutions Limited | Information & communication | 2023 |
| Vacfix Ltd | Manufacturing | 2018 |
| Vaddakachchi Central College OSA (UK) Ltd | Education | 2021 |
| VAG Tune Services Ltd | Wholesale & retail | 2019 |
| Vaien Technology Limited | Information & communication | 2014 |
| Vakratunda Properties Ltd | Real estate | 2024 |
| Vale Brewery Company Ltd. | Manufacturing | 2013 |
| Vale Burner Services Ltd | Manufacturing | 2012 |
| Vale Comms & Data Ltd | Information & communication | 2007 |
| Vale Consultancy Services Limited | Extraterritorial | 2009 |
| Vale Dance Academy Ltd | Arts & recreation | 2025 |
| Vale Security Ltd | Administrative & support | 2016 |
| Vale Support Services Limited | Information & communication | 2013 |
| Vale Travel Limited | Transport & logistics | 2013 |
| Valentin Construction Ltd | Construction | 2014 |
| Valentine Clark Interior Design Ltd | Extraterritorial | 2025 |
| Valex Properties Ltd | Real estate | 2023 |
| Valley Pumps Limited | Water & waste | 2014 |
| Valmont Advisory Ltd | Administrative & support | 2026 |
| Valor Advisory Limited | Professional & scientific | 2025 |
| Valsi Ltd | Other services | 2025 |
| Valteo Fixx Ltd | Construction | 2020 |
| Valuable.Com Limited | Wholesale & retail | 2000 |