| Ubique Plumbing & Heating Ltd | Construction | 2019 |
| Ubiquity Finance Limited | Financial services | 2012 |
| Uche by Amber Ltd | Wholesale & retail | 2025 |
| UCS Sameday Limited | Transport & logistics | 2007 |
| Uday Transport Ltd | Transport & logistics | 2026 |
| Udriveme-Vr Ltd | Education | 2024 |
| UDS (NO 10) | Financial services | 1984 |
| UDS (NO 3) Limited | Professional & scientific | 1899 |
| UDS Corporation Limited | Financial services | 1993 |
| UDS Finance Limited | Financial services | 1947 |
| UDS Group Limited | Financial services | 1983 |
| UDS Holdings (1) Limited | Financial services | 1989 |
| UGI Group Limited | Professional & scientific | 1989 |
| UHS Structures Ltd | Construction | 2023 |
| Uhuru United Ltd. | Information & communication | 2018 |
| UK Automotive Solutions Limited | Administrative & support | 2023 |
| UK Compassionate Care Limited | Health & social care | 2024 |
| UK Covered Car Transport Ltd | Transport & logistics | 2025 |
| UK India Trade Connect Limited | Wholesale & retail | 2025 |
| UK Pharmacovigilance Services Provider Limited | Health & social care | 2014 |
| UK Poster Distribution Ltd | Professional & scientific | 2019 |
| UK Trading London Ltd | Wholesale & retail | 2011 |
| UK Tyres Ltd | Extraterritorial | 2018 |
| Uk.Shaba's Construction Limited | Construction | 2017 |
| Ukholo Consultancy Ltd | Professional & scientific | 2023 |
| ULT Sales Ltd | Wholesale & retail | 2026 |
| Ultimate Car Control UK Limited | Education | 2006 |
| Ultimate Strategic Partnerships Ltd | Professional & scientific | 2017 |
| Ultra Cyber Limited | Manufacturing | 2022 |
| Ultreia Life Sciences Consulting Ltd | Professional & scientific | 2025 |
| Ulyssez Properties Ltd | Real estate | 2020 |
| Umia Trade Ltd | Wholesale & retail | 2025 |
| UNA Service Charge Management Ltd | Real estate | 2025 |
| Uncle Jays Toys Store Ltd | Wholesale & retail | 2024 |
| UNDERD0G Manufacture Ltd | Other services | 2020 |
| Unicorn Associates Ltd | Real estate | 2025 |
| Unik Construction Limited | Construction | 2024 |
| Union Art Ltd | Wholesale & retail | 2011 |
| Unique London Design & Build Limited | Construction | 2017 |
| Unique London Homes Limited | Extraterritorial | 2025 |
| Unisys Consulting Limited | Information & communication | 2016 |
| Unit 1 Flooring Ltd | Wholesale & retail | 2021 |
| Unite Building Limited | Construction | 2023 |
| United Concrete Pumping Limited | Wholesale & retail | 2019 |
| United GAS Industries Limited | Professional & scientific | 1929 |
| United Kingdom Tyre Exporters Limited | Wholesale & retail | 1970 |
| United Kingdom Tyres Ltd | Extraterritorial | 2017 |
| United Waste Property Limited | Extraterritorial | 1996 |
| Unity Arabic Gums Ltd | Wholesale & retail | 2026 |
| Unity Property Development Ltd | Real estate | 2024 |
| Unity School of Christianity of Great Britain | Other services | 1947 |
| Universal Finance Limited | Financial services | 2023 |
| Universal Real Estate Limited | Real estate | 1999 |
| UNO Corsa Ltd | Wholesale & retail | 2025 |
| UP the Ante Limited | Professional & scientific | 2007 |
| Uplift Community Co Limited | Professional & scientific | 2016 |
| Upper Western Logistics Limited | Transport & logistics | 2017 |
| Upperline Marketing Limited | Professional & scientific | 2016 |
| Upside Avenue Ltd | Real estate | 2019 |
| Upside Barbers Ltd | Other services | 2025 |
| Upstream Aquatics Ltd | Agriculture & fishing | 2023 |
| Upton Adventure Golf Ltd | Arts & recreation | 2023 |
| Upup-K Ltd | Wholesale & retail | 2023 |
| Upvisors Ltd | Information & communication | 2017 |
| Urban Living Accommodation Ltd | Administrative & support | 2017 |
| Urban Vista Planning Ltd | Professional & scientific | 2017 |
| URU Home UK Ltd | Wholesale & retail | 2018 |
| Usemaxi Limited | Manufacturing | 2000 |
| Ushyma Sylvan Limited | Construction | 2022 |
| Utelly Limited | Administrative & support | 2013 |
| UTI Partnership Limited | Health & social care | 2026 |
| Utility Network Infrastructures Ltd | Construction | 2024 |
| UX Affinity Ltd | Information & communication | 2022 |
| V-Ixtech Consulting Ltd | Professional & scientific | 2022 |
| V. Lockwood Carpentry Ltd | Construction | 2018 |
| V2S Real Company Ltd | Administrative & support | 2025 |
| V3 Homes Ltd | Real estate | 2025 |
| V5 Nails Ltd | Other services | 2024 |
| Vacant Property Compliance Limited | Households | 2026 |
| Vacation Finance Limited | Financial services | 2015 |
| Vahaa Tech Limited | Wholesale & retail | 2023 |
| Vailly Limited | Real estate | 2023 |
| Valdenize Soares Ltd | Wholesale & retail | 2019 |
| Vale of Leven Wind Farm Limited | Energy | 2019 |
| Vale Retail House Ltd | Real estate | 2025 |
| Valegold Investments Limited | Real estate | 2004 |
| Valiant Property Services Limited | Extraterritorial | 2024 |
| Valiant Recruitment Limited | Administrative & support | 2022 |
| Validate Systems Limited | Administrative & support | 2002 |
| Valley Appliances Ltd | Other services | 2026 |
| Valley Associated Travel Limited | Transport & logistics | 1993 |
| Vamsh Consulting Limited | Professional & scientific | 2019 |
| Vanchilla Services Limited | Manufacturing | 1983 |
| Vanilla Cakes Limited | Manufacturing | 2022 |
| Vanni Properties Ltd | Real estate | 2020 |
| Vantage Procurement Ltd | Professional & scientific | 2022 |
| Varang Properties Limited | Real estate | 2021 |
| Varney & SON Construction Ltd | Construction | 2019 |
| Varta Beauty Clinic Limited | Other services | 2026 |
| Varu PL Ltd | Construction | 2017 |