| Unstylo Limited | Construction | 2016 |
| Unthank Distillery Limited | Manufacturing | 2018 |
| Unthank Hair Ltd | Other services | 2020 |
| Unthank Speech & Communication Ltd | Health & social care | 2023 |
| Untold Engineering Ltd | Professional & scientific | 2019 |
| Unum Holdings Limited | Financial services | 2025 |
| Unwedding Festival CIC | Arts & recreation | 2021 |
| UP a Creek Plumbing & Heating Ltd | Construction | 2019 |
| UP the Garden Company Ltd | Wholesale & retail | 2021 |
| UP the Tempo Running Community Interest Company | Education | 2018 |
| UP2U2 Limited | Extraterritorial | 2014 |
| Upcore Limited | Information & communication | 2026 |
| Upheat Plumbing & Heating Ltd | Construction | 2020 |
| Uphill Struggles Ltd | Wholesale & retail | 2018 |
| Uphire UK Limited | Other services | 2021 |
| Uphouse Farm Limited | Agriculture & fishing | 1997 |
| Upmission CIC | Education | 2025 |
| Upper Ridings Limited | Professional & scientific | 2003 |
| Upper ST Giles RTM Company Ltd | Households | 2003 |
| Upper Street Limited | Real estate | 2022 |
| Upright Insight Ltd | Professional & scientific | 2025 |
| Upstairs at the Sailing Club Limited | Hospitality | 2026 |
| Upstairs at the Sailing Club Southwold Ltd | Hospitality | 2025 |
| Upsurge Ltd | Arts & recreation | 2018 |
| Upthinkers Ltd | Professional & scientific | 2014 |
| Upton Composite Solutions Limited | Manufacturing | 2019 |
| Upvio Healthtech Limited | Financial services | 2022 |
| UR Choice Care Ltd | Administrative & support | 2011 |
| Urban Agents Limited | Real estate | 2015 |
| Urban Chapter Developments Limited | Real estate | 2023 |
| Urban Context Design Ltd | Professional & scientific | 2019 |
| Urban Electrical and Renewables Ltd | Professional & scientific | 2025 |
| Urban FOX Consultancy Ltd | Professional & scientific | 2023 |
| Urban Fuse Electrical Ltd | Construction | 2013 |
| Urban Green Equities Ltd | Real estate | 2024 |
| Urban Jungle Nursery Ltd | Wholesale & retail | 2018 |
| Urban Lighting Limited | Construction | 2015 |
| Urban Lounge Ltd | Hospitality | 2024 |
| Urban Myth Angling Limited | Agriculture & fishing | 2013 |
| Urban Regeneration (Anglia) Limited | Construction | 2007 |
| Urban Regeneration (East) Limited | Construction | 2007 |
| Urban Rural LMC Ltd | Professional & scientific | 2016 |
| Urban Stays Norfolk Limited | Hospitality | 2020 |
| Urbanavitcha Limited | Manufacturing | 2008 |
| Urbanday Holdings Ltd | Real estate | 2016 |
| Urchins Catering Limited | Hospitality | 2025 |
| Urian Ltd | Manufacturing | 2022 |
| Urology East Limited | Health & social care | 2018 |
| Uropharma (UK) Limited | Manufacturing | 2024 |
| Uropharma Limited | Manufacturing | 2012 |
| Ursa Construction Ltd | Construction | 2023 |
| Ursa U.K. Limited | Manufacturing | 1999 |
| Ursula Tucker Architect Limited | Professional & scientific | 2018 |
| US Chicken and Grill Ltd | Hospitality | 2024 |
| US2U Consulting Limited | Professional & scientific | 2005 |
| USA Catering Limited | Hospitality | 2019 |
| USE Solutions Limited | Professional & scientific | 2019 |
| Used Designer Fashion Ltd | Wholesale & retail | 2024 |
| Useful Logistic RRL Ltd | Transport & logistics | 2025 |
| User Interface Ltd | Information & communication | 2022 |
| Ushercare Limited | Health & social care | 2017 |
| Uslu Accommodation Norwich Limited | Hospitality | 2023 |
| Ussons Ltd | Arts & recreation | 2021 |
| Utec Survey West Africa Limited | Professional & scientific | 2016 |
| Utilise (Utility Contracting) Ltd | Construction | 2011 |
| Utilities Care Limited | Wholesale & retail | 2018 |
| Utku Active Limited | Education | 2020 |
| Utopia Voyages Ltd | Administrative & support | 2023 |
| UTS Cable Limited | Manufacturing | 2006 |
| Utting Construction Ltd | Construction | 2024 |
| Uttlesford Norse Services Limited | Administrative & support | 2020 |
| UV Guard Ltd | Water & waste | 2025 |
| V & a Building Limited | Construction | 2014 |
| V for Vets Ltd | Professional & scientific | 2024 |
| V G N Consultants Ltd | Real estate | 2017 |
| V Networks Communications Limited | Information & communication | 2011 |
| V&V Fast Logistic Ltd | Transport & logistics | 2016 |
| V&V Logic Limited | Transport & logistics | 2025 |
| V.Ernest Building Services Ltd | Construction | 2016 |
| V22STJ Ltd | Administrative & support | 2024 |
| V33 Autolocks Ltd | Wholesale & retail | 2025 |
| V8 Music Limited | Extraterritorial | 2026 |
| V99 Investments Limited | Real estate | 2020 |
| VA Dimensional Services Ltd | Professional & scientific | 2026 |
| Vaalbank Properties Ltd | Real estate | 2018 |
| Vaar Design Ltd | Professional & scientific | 2025 |
| Vacia Ltd | Transport & logistics | 2024 |
| Vagabond Escapes Ltd | Hospitality | 2024 |
| Vaia Construct Ltd | Construction | 2019 |
| Vaka Limited | Other services | 2015 |
| Vakosha Ltd | Information & communication | 2016 |
| Vakta Ltd | Professional & scientific | 2026 |
| VAL Design and Create Future Limited | Manufacturing | 2010 |
| VAL Fitting Ltd | Construction | 2018 |
| Valemount Properties Limited | Construction | 2007 |
| Valentis Investments Ltd | Real estate | 2021 |
| Valeo Confectionery Limited | Manufacturing | 1986 |
| Vales Tools and Consumables Limited | Wholesale & retail | 2023 |
| Valhalla Clothing Limited | Extraterritorial | 2018 |
| Valhalla Lawyers Limited | Manufacturing | 2025 |