| Tyranno 2 Limited | Information & communication | 2024 |
| Tyre Shop Harlow Limited | Wholesale & retail | 2026 |
| Tyrone Consultants Ltd | Construction | 2011 |
| Tzpartyhire Limited | Administrative & support | 2025 |
| TZR Ltd | Wholesale & retail | 2024 |
| U K Okoli Co. Ltd | Health & social care | 2010 |
| U L Properties Limited | Real estate | 2023 |
| U Need Systems Ltd | Information & communication | 1995 |
| U-Cook Global Ltd | Wholesale & retail | 2021 |
| U-Trade Global Ltd | Wholesale & retail | 2022 |
| Uatw Limited | Information & communication | 2025 |
| Uavaid Limited | Professional & scientific | 2014 |
| Ubix Limited | Information & communication | 2023 |
| UCS Property Investment Group Ltd | Construction | 2019 |
| UD Estates Ltd | Real estate | 2017 |
| UDP Sorriso Ltd | Health & social care | 2015 |
| UGP Investments Limited | Financial services | 2019 |
| UJT Investments Ltd | Real estate | 2024 |
| UJT Limited | Wholesale & retail | 2010 |
| UK Airport Cars Limited | Transport & logistics | 2006 |
| UK and British Estates Ltd | Real estate | 2015 |
| UK Consulting Courses and Qualifications Ltd | Construction | 2019 |
| UK Direct 24/7 Ltd | Wholesale & retail | 2014 |
| UK Discoveries Ltd | Wholesale & retail | 2021 |
| UK Frontline Limited | Financial services | 2016 |
| UK Future Footprints Limited | Health & social care | 2025 |
| UK Gadget Shop Limited | Wholesale & retail | 2019 |
| UK London Private Hire Limited | Transport & logistics | 2019 |
| UK Masu Limited | Administrative & support | 2018 |
| UK Naans Ltd | Wholesale & retail | 2026 |
| UK OB Ltd | Professional & scientific | 2017 |
| UK Padel Distribution Ltd | Manufacturing | 2024 |
| UK Paramount Limited | Real estate | 2021 |
| UK Property Consultants Ltd | Households | 2024 |
| UK Quality Tyres Ltd | Wholesale & retail | 2023 |
| UK Wheels Limited | Wholesale & retail | 2019 |
| Ukare Physiorehab Ltd | Other services | 2023 |
| Ukdeals Direct Ltd | Wholesale & retail | 2014 |
| Ukrainian Armor Ltd | Public administration | 2018 |
| Ukrbud Ltd | Construction | 2022 |
| ULC World Limited | Education | 2020 |
| Ulsterville Property Limited | Hospitality | 2024 |
| UM Pharm Ltd | Health & social care | 2025 |
| Umaris Property Group Limited | Real estate | 2021 |
| UMR Wholesale Limited | Extraterritorial | 2013 |
| Umrah Ventures Ltd | Administrative & support | 2024 |
| Umrah Vision Ltd | Administrative & support | 2024 |
| UN Salto a Londres - Jump to London Ltd | Hospitality | 2018 |
| Unbox Fourteen Ltd | Information & communication | 2022 |
| Uncol Ltd | Education | 2015 |
| Uncomplicated Skincare Ltd | Wholesale & retail | 2021 |
| Under Pressure Events Ltd | Administrative & support | 2026 |
| Underwater Properties Limited | Real estate | 1988 |
| Underwood Audio Ltd | Arts & recreation | 2019 |
| UNI Suyog Communications Limited | Information & communication | 2021 |
| Unibar Restaurant Limited | Hospitality | 2003 |
| Unicorn Communications Infra Limited | Information & communication | 2023 |
| Unicorn Luggage Ltd | Wholesale & retail | 2024 |
| Unicorn Supplies Ltd | Wholesale & retail | 2021 |
| Unidate Limited | Wholesale & retail | 1998 |
| Unify Consultancy Services Limited | Information & communication | 2020 |
| Unileaf Limited | Professional & scientific | 2003 |
| Union General Properties(Overseas)Limited | Professional & scientific | 1961 |
| Uniplex Ventures Limited | Real estate | 2002 |
| Unique & Bright Innovations Private Limited | Real estate | 2025 |
| Unique Auto Trade Ltd | Wholesale & retail | 2024 |
| Unique Barber Limited | Other services | 2014 |
| Unique Builder Master Ltd | Construction | 2024 |
| Unique Global Services Ltd | Financial services | 2019 |
| Unique Products Kingdom Ltd | Wholesale & retail | 2025 |
| Unique Sky Cars Ltd | Wholesale & retail | 2025 |
| UNIS-VCOM02 Ltd | Wholesale & retail | 2021 |
| Unisdrive Ltd | Information & communication | 2015 |
| Unisempire Evolutions Group Limited | Information & communication | 2016 |
| Unisex Hair and Beauty Limited | Other services | 2023 |
| Unishost Ltd. | Information & communication | 2014 |
| Unisillusions Limited | Information & communication | 2016 |
| Unislance Ltd | Information & communication | 2015 |
| Uniss Education Limited | Information & communication | 2021 |
| Unissense Ltd | Wholesale & retail | 2011 |
| Unissvcom Ltd | Wholesale & retail | 2022 |
| Unistar Retail Ltd | Wholesale & retail | 2025 |
| Unistar Wholesale Ltd | Wholesale & retail | 2015 |
| Unistronics Limited | Information & communication | 2021 |
| Uniswings Limited | Information & communication | 2021 |
| Unit Exchange Limited | Wholesale & retail | 2014 |
| United Globally | Administrative & support | 2021 |
| United Kingdom Sport Chanbara Federation Ltd | Arts & recreation | 2022 |
| United Wellness Ltd | Health & social care | 2024 |
| Uniti Housing C.I.C. | Real estate | 2024 |
| Unity Stock Limited | Wholesale & retail | 2023 |
| Unity Works Global Ltd | Administrative & support | 2026 |
| Universal Academic Services Ltd | Professional & scientific | 2022 |
| Universal Genomics Ltd | Professional & scientific | 2026 |
| Universal Legacy Property Ltd | Real estate | 2025 |
| Universal Payment Solution Limited | Information & communication | 2014 |
| Universal Retail Group Ltd | Wholesale & retail | 2023 |
| Universal Service Stations Ltd | Administrative & support | 2017 |
| Universal Suppliers Limited | Wholesale & retail | 2003 |
| Universal Trade Supplies Limited | Administrative & support | 2006 |