| U Rohaan Limited | Information & communication | 2020 |
| U&B Properties Ltd | Real estate | 2024 |
| U-Explore Limited | Education | 2013 |
| UAB Legal Services Limited | Professional & scientific | 2026 |
| Uber Agency Limited | Professional & scientific | 2003 |
| Uber Freelance Limited | Other services | 2018 |
| Uberhair and Training Services Limited | Other services | 2017 |
| Ucprestige Limited | Administrative & support | 2015 |
| UH Financial Services Ltd | Professional & scientific | 2017 |
| UK Baggys Limited | Wholesale & retail | 2024 |
| UK Burger Ltd | Hospitality | 2024 |
| UK Empire Properties Limited | Real estate | 2021 |
| UK Official Gamesir Ltd | Wholesale & retail | 2025 |
| UK Recycling SY Limited | Wholesale & retail | 2019 |
| UK Simulators Limited | Hospitality | 2002 |
| UK Tax Accountants Limited | Professional & scientific | 2010 |
| UK Tax Accounting Limited | Professional & scientific | 2013 |
| UK Tax Parasol Ltd | Financial services | 2017 |
| UK Telugu Talkies Ltd | Information & communication | 2025 |
| UK Truckwash Ltd | Extraterritorial | 2008 |
| UK Wrestling Entertainment Limited | Hospitality | 2020 |
| Uk.Contracting Solutions Ltd | Administrative & support | 2023 |
| Uk.Health First Limited | Health & social care | 2025 |
| Ukct Limited | Wholesale & retail | 2021 |
| Ukexpress Logistics Services Limited | Administrative & support | 2021 |
| UKW Studios Limited | Information & communication | 2024 |
| Ultimate Asset Management Limited | Real estate | 2020 |
| Ultimate Energy Ltd | Other services | 2013 |
| Ultimate Glass Limited | Manufacturing | 2006 |
| Ultra Accountancy Limited | Professional & scientific | 2016 |
| Ultra One Heating and Air Conditioning Ltd | Construction | 2019 |
| Ultramax Products Limited | Professional & scientific | 2005 |
| Ultramax Property Holdings Limited | Real estate | 2013 |
| UM Products Ltd | Manufacturing | 2010 |
| Umar Halal Butchers Limited | Wholesale & retail | 2023 |
| Umbra Catering Limited | Hospitality | 2026 |
| Umbrella - Family Centre CIC | Professional & scientific | 2017 |
| Umgawa Ltd | Professional & scientific | 2019 |
| Umpleby Groundworks Ltd | Administrative & support | 2026 |
| UMS Pressevertrieb Limited | Professional & scientific | 2010 |
| Umsakazo Records Limited | Information & communication | 2016 |
| Unbeatable Car Buyer Limited | Professional & scientific | 2011 |
| Uncast Ltd | Wholesale & retail | 2023 |
| Unchained Performance Ltd | Wholesale & retail | 2026 |
| Unclejyde Kiddies Limited | Wholesale & retail | 2021 |
| Underside Ltd | Wholesale & retail | 2025 |
| Unes Healthcare Limited | Health & social care | 2023 |
| Unglutened Bakers Ltd | Manufacturing | 2026 |
| Unicco Medicals Ltd | Health & social care | 2023 |
| Unicorn Beauty Limited | Other services | 2014 |
| Unicorn Properties Yorkshire Limited | Real estate | 2003 |
| Unifleet Utility Solutions Ltd | Wholesale & retail | 2013 |
| Uniflo Products Limited | Wholesale & retail | 2014 |
| Unique Beds Limited | Manufacturing | 2023 |
| Unique Dining Group International Ltd | Manufacturing | 2021 |
| Unique Marketing Service Ltd | Extraterritorial | 2016 |
| Unique Property (Wakefield) Limited | Construction | 2025 |
| Unis Pharma Ltd | Health & social care | 2012 |
| United Autosports Limited | Professional & scientific | 2009 |
| United Autosports Special Projects Limited | Arts & recreation | 2025 |
| United Historics Limited | Extraterritorial | 2013 |
| United Parcels Leeds Limited | Transport & logistics | 2021 |
| United Security Group UK Ltd | Wholesale & retail | 2017 |
| United Transmission Services Limited | Wholesale & retail | 1989 |
| Units UK Group Limited | Financial services | 2026 |
| Unity Bars and Clubs Ltd | Hospitality | 2016 |
| Unity Chesterfield Ltd | Administrative & support | 2018 |
| Unity Electrical Limited | Construction | 2005 |
| Unity Hall and Business Space Ltd | Real estate | 2018 |
| Unity Hall Partnership LLP | | 2025 |
| Unity Home Improvement Network Limited | Construction | 2021 |
| Unity Properties Ltd | Real estate | 2022 |
| Unity Retail Leeds Ltd | Hospitality | 2026 |
| Universal Neuro Express Ltd | Health & social care | 2023 |
| Universal Office Products Ltd | Wholesale & retail | 2002 |
| Upjees Limited | Financial services | 2011 |
| Upperyork Educational Centre Ltd | Education | 2024 |
| Upserv Limited | Professional & scientific | 2014 |
| Upvc Maintenance (Rotherham) Limited | Real estate | 2018 |
| Upvc Maintenance Supplies Limited | Extraterritorial | 2018 |
| Upward Properties Limited | Construction | 2011 |
| Urban Joinery JG Building Limited | Construction | 2018 |
| Urban Sturgeon Ltd | Professional & scientific | 2019 |
| Urban Tile Nationwide Ltd | Wholesale & retail | 2024 |
| Urban Tile Wakefield Ltd | Wholesale & retail | 2026 |
| Urbat Home and Property Limited | Administrative & support | 2005 |
| Ursa Major Limited | Professional & scientific | 2026 |
| Uruz Holdings Ltd | Construction | 2023 |
| Used Garage Equipment UK Ltd | Wholesale & retail | 2024 |
| Usman ALI Ltd | Wholesale & retail | 2025 |
| Utile Consultancy Limited | Professional & scientific | 2017 |
| Utility Training (Yorkshire) Ltd | Professional & scientific | 2021 |
| Utley Excavations Ltd | Construction | 2010 |
| V & R Brickwork Ltd | Construction | 2026 |
| V S. Immobilien Limited | Administrative & support | 2007 |
| V Timber Ltd | Wholesale & retail | 2013 |
| V&L Interior Ltd | Construction | 2024 |
| V2 Homes Ltd | Real estate | 2016 |
| Vaitehue Ltd | Wholesale & retail | 2025 |
| Vale Projects & Services LLP | | 2021 |