| UK Smart Choice Trading Ltd | Wholesale & retail | 2026 |
| UK SSI Ltd | Administrative & support | 2022 |
| UK Star Limited | Wholesale & retail | 2007 |
| UK Supplies & Services Limited | Information & communication | 2006 |
| UK Sweet One Ltd | Wholesale & retail | 2020 |
| UK Tamil Awards Ltd | Administrative & support | 2024 |
| UK Tara Ltd | Wholesale & retail | 2019 |
| UK Tax Accountancy Ltd | Professional & scientific | 2022 |
| UK Tech Consultants Limited | Information & communication | 2023 |
| UK Telecom Services Limited | Information & communication | 2017 |
| UK Textile & Hosiery Ltd | Wholesale & retail | 2022 |
| UK TK Limited | Wholesale & retail | 2023 |
| UK Trained Security Ltd | Administrative & support | 2023 |
| UK Travel Cart Limited | Administrative & support | 2024 |
| UK Utility Factory Ltd | Other services | 2018 |
| UK V.A.M Developments Ltd | Construction | 2020 |
| UK VEG Ltd | Wholesale & retail | 2020 |
| UK Vehicle Hire Ltd | Administrative & support | 2019 |
| UK Visa Application Center Ltd | Professional & scientific | 2024 |
| UK Wholesavers Ltd | Wholesale & retail | 2024 |
| Ukademic Education Limited | Administrative & support | 2025 |
| Ukaibi Limited | Wholesale & retail | 2025 |
| Ukanah Prime Limited | Manufacturing | 2025 |
| Ukbd Export & Import Ltd | Wholesale & retail | 2018 |
| Ukcc Group Ltd | Administrative & support | 2025 |
| Ukcdma CIC | Administrative & support | 2025 |
| Ukcsp Ltd | Health & social care | 2019 |
| UKD Groundworks & Civil Engineering Limited | Construction | 1999 |
| Ukfs Consulting Limited | Professional & scientific | 2009 |
| Ukites by PBC Limited | Information & communication | 2021 |
| UKM Limited | Professional & scientific | 2002 |
| Ukpainters Ltd | Construction | 2021 |
| UKPROPERTY4U Ltd | Real estate | 2021 |
| Uktncc Limited | Other services | 2013 |
| UL Vision Ltd | Wholesale & retail | 2025 |
| Ullah Corporation Limited | Real estate | 2025 |
| Ultimate Blasters Ltd | Information & communication | 2020 |
| Ultimate Fit Ltd | Other services | 2024 |
| Ultimate IT Services Ltd | Information & communication | 2021 |
| Ultimate Management Facilities Ltd | Real estate | 2016 |
| Ultimate Stores Limited | Wholesale & retail | 2013 |
| Ultimate Style Limited | Real estate | 2022 |
| Ultimate Umbrella Limited | Wholesale & retail | 2020 |
| Ultra Construction Group Ltd | Construction | 2019 |
| Ultra Health Systems Limited | Wholesale & retail | 2011 |
| Ultra Security Services Ltd | Administrative & support | 2019 |
| Ultra Shine Cleaning Services Limited | Administrative & support | 2025 |
| Ultra Stream Technologies Limited | Wholesale & retail | 2024 |
| Ultrasound Today Ltd | Health & social care | 2026 |
| Ultron Fire and Security Ltd | Construction | 2017 |
| Ulvermoor Ltd | Other services | 2007 |
| UM Electrical Ltd | Construction | 2023 |
| UM Sportswear Ltd | Wholesale & retail | 2024 |
| Umaad Sheikh Law Ltd | Professional & scientific | 2025 |
| Umai Cart Ltd | Wholesale & retail | 2026 |
| Umair Coffee Ltd | Hospitality | 2025 |
| Umami PAN Asian Cuisine Ltd | Extraterritorial | 2018 |
| Umar Design and Build Limited | Construction | 2018 |
| Umar Education Group Ltd | Education | 2023 |
| Umar IBN Alkhattab Academy Ltd | Education | 2025 |
| Umashiva Ltd | Real estate | 2025 |
| UMB Construction Ltd | Construction | 2025 |
| Umbrella Food Ltd | Other services | 2022 |
| Umbrella Sense Limited | Professional & scientific | 2019 |
| UME Associates Ltd | Professional & scientific | 2025 |
| UME Fashion Limited | Wholesale & retail | 2016 |
| Umer Builders & Contractors Ltd | Construction | 2012 |
| Umer E-Commerce Ltd | Wholesale & retail | 2023 |
| Umer Trading Room Ltd | Wholesale & retail | 2025 |
| Umesh Joshi Limited | Information & communication | 2013 |
| Ummah Care & Support Limited | Health & social care | 2013 |
| Ummah Meats and Groceries Ltd | Manufacturing | 2025 |
| Ummah Travel Limited | Administrative & support | 2009 |
| Ummat Autos Limited | Wholesale & retail | 2019 |
| Umme Construction Services Limited | Construction | 2019 |
| Umnah Accountant Ltd | Other services | 2025 |
| Umove Property Services Ltd | Real estate | 2010 |
| UMP Trading Limited | Wholesale & retail | 2025 |
| Umqad Group Ltd | Real estate | 2024 |
| Umrah Express Ltd | Administrative & support | 2015 |
| UMS Boat UK Limited | Wholesale & retail | 2020 |
| Umsak Group Ltd | Construction | 2018 |
| Unblock Drainage Ltd | Water & waste | 2025 |
| Unchartered Solutions Ltd | Real estate | 2025 |
| Uncle John's Bakery Limited | Wholesale & retail | 2008 |
| Under Construction Services Ltd | Hospitality | 2025 |
| Underground Sweets and C0 Ltd | Wholesale & retail | 2024 |
| Undergroundvapes Ltd | Wholesale & retail | 2022 |
| Unecom Limited | Information & communication | 2024 |
| Unee Facility Management Ltd | Administrative & support | 2021 |
| UNG Decorating Ltd | Construction | 2022 |
| UNI Consultancy and Services Limited | Professional & scientific | 2012 |
| UNI Matchers Ltd | Education | 2024 |
| Uni.Brando Limited | Wholesale & retail | 2025 |
| Unibee Limited | Education | 2026 |
| Uniclinic Limited | Health & social care | 2011 |
| Unicorn Build Ltd | Households | 2023 |
| Unicorn Property Holdings Ltd | Real estate | 2023 |
| Unicorn Rock Limited | Wholesale & retail | 2023 |
| Unicorn Technology Ltd | Wholesale & retail | 2025 |