| UK Used Car Parts Ltd | Manufacturing | 2026 |
| UK Woodmaster Ltd | Construction | 2019 |
| UK. Surgical Consultants Limited | Health & social care | 2004 |
| Uk.P.T.Transport Ltd | Transport & logistics | 2025 |
| Ukjuicers W11 Limited | Wholesale & retail | 2019 |
| UKR Trans Kosta Ltd | Transport & logistics | 2025 |
| Uksimple Limited | Information & communication | 2007 |
| Ulez Free Cars Ltd | Transport & logistics | 2023 |
| Ullmore Limited | Information & communication | 2013 |
| Ulmus Farm Limited | Other services | 2013 |
| ULT Projects Ltd | Construction | 2003 |
| ULT Trading Company Limited | Arts & recreation | 2009 |
| Ultimate Broker Services Ltd | Wholesale & retail | 2023 |
| Ultimate Fabrication Ltd | Manufacturing | 2021 |
| Ultimate Fire Solutions Limited | Administrative & support | 2025 |
| Ultimate Heating Services Ltd | Other services | 2016 |
| Ultimate Performance Lifestyle Limited | Administrative & support | 2012 |
| Ultimate PT Training Ltd | Education | 2016 |
| Ultra Gloss Detailing Ltd | Wholesale & retail | 2025 |
| UM Asset Management Limited | Real estate | 2025 |
| UM Living Limited | Real estate | 2019 |
| Umaimah Ltd | Real estate | 2026 |
| Umair Trading Ltd | Hospitality | 2025 |
| Umar & Sons Trading Co. Ltd | Wholesale & retail | 2023 |
| Umar Investments Ltd | Real estate | 2022 |
| UMI Corals Limited | Wholesale & retail | 2018 |
| Ummah Halal Ltd | Wholesale & retail | 2018 |
| UMS Pharmaceutical Ltd | Professional & scientific | 2026 |
| Umuakagu Welfare UK Ltd | Health & social care | 2025 |
| Unbound Adaptive CIC | Wholesale & retail | 2026 |
| Unbranded Collective Limited | Administrative & support | 2020 |
| Uncle B’S Caribbean Flava’S Ltd | Hospitality | 2026 |
| Uncommon Inc Ltd | Wholesale & retail | 2020 |
| Unconventional Conventions Limited | Administrative & support | 2024 |
| Under HIS Wings Ltd | Wholesale & retail | 2022 |
| Under the Eagle Ltd | Hospitality | 2021 |
| Underhay Consulting Ltd | Information & communication | 2026 |
| Underwood (Peterborough) Limited | Construction | 2009 |
| UNI Abode Ltd | Real estate | 2017 |
| UNI Assist Ltd | Construction | 2007 |
| Unicorn Study Abroad UK Limited | Education | 2024 |
| Unify Recruitment Group Ltd | Administrative & support | 2024 |
| Union Car Sales Ltd | Wholesale & retail | 2025 |
| Union Carz Limited | Transport & logistics | 2021 |
| Uniprod Management Limited | Wholesale & retail | 2013 |
| Unique Choice Building & Maintenance Ltd | Construction | 2022 |
| Unique Choice Distribution Limited | Wholesale & retail | 2019 |
| Unique Horizons Digital Ltd | Wholesale & retail | 2025 |
| Unique Key Limited | Professional & scientific | 2018 |
| Unique Taxi Service Ltd | Transport & logistics | 2026 |
| Uniquities Ltd | Wholesale & retail | 2003 |
| Unirox Group Limited | Administrative & support | 2023 |
| UNITB9 Limited | Wholesale & retail | 2022 |
| Unite 4 Humanity | Health & social care | 2013 |
| Unite Services Ltd | Administrative & support | 2023 |
| United Church Schools Trust | Education | 1993 |
| United Communities | Education | 2025 |
| United Counties Football League | Arts & recreation | 2012 |
| United Flooring Peterborough Limited | Wholesale & retail | 2012 |
| United Learning Ltd | Real estate | 1883 |
| United Learning Trust | Education | 2002 |
| United Lusophone African Voices Community Interest Company | Other services | 2025 |
| Unitsector Residents Management Limited | Households | 1987 |
| Unity Point Services Ltd | Administrative & support | 2026 |
| Universal Bakers Limited | Wholesale & retail | 2026 |
| Universal Links Ltd | Transport & logistics | 1998 |
| Universal Supply Hub Ltd | Wholesale & retail | 2025 |
| Universal Trade Centre Ltd | Transport & logistics | 2010 |
| University Centre Peterborough | Education | 2007 |
| Unix Global Services Ltd | Wholesale & retail | 2019 |
| Unleashing Real Leadership Ltd | Professional & scientific | 2023 |
| Unlimited Business Endeavours Ltd | Hospitality | 2025 |
| Unlimited Glow Ltd | Wholesale & retail | 2021 |
| Unlimited Success Ventures Limited | Education | 2016 |
| Unlock Profit Online Ltd | Wholesale & retail | 2024 |
| Unseen Art Ltd | Wholesale & retail | 2016 |
| Unspoken Atiq Ltd | Professional & scientific | 2024 |
| Unwin Rectory Ltd | Construction | 2018 |
| UP the Garden Bath Community Interest Company | Construction | 2020 |
| UP the Poshcast Ltd | Information & communication | 2025 |
| Upholstery Services Sebastian Ltd | Other services | 2025 |
| Upperton Care UK Limited | Health & social care | 2016 |
| Upsize Property Renovation Ltd | Construction | 2024 |
| Upton Car Sales Ltd | Wholesale & retail | 2024 |
| Upump Limited | Wholesale & retail | 2019 |
| Urban Adept Limited | Professional & scientific | 2025 |
| Urban and Elite UK Ltd | Wholesale & retail | 2025 |
| Urban Cleaning Liverpool Limited | Administrative & support | 2025 |
| Urban Cleaning Peterborough Limited | Administrative & support | 2022 |
| Urban Glass Group Ltd | Construction | 2026 |
| Urban Gorilla Events Ltd | Wholesale & retail | 2026 |
| Urban Homes Management Ltd | Real estate | 2018 |
| Urban Interiors Ltd | Professional & scientific | 2020 |
| Urban Stay SA Limited | Hospitality | 2023 |
| Urban Taste Ltd | Hospitality | 2022 |
| Urban Villages Development Ltd | Construction | 2015 |
| Urbancore Holdings Ltd | Financial services | 2025 |
| Urbandel Limited | Transport & logistics | 2026 |
| Urbex Rides Limited | Transport & logistics | 2025 |
| Urelectrics Ltd | Construction | 2022 |