| Unibrid Heating & Cooling Company Ltd | Wholesale & retail | 2024 |
| Unicowd Ltd | Information & communication | 2020 |
| Unique Corporate Ltd | Information & communication | 2005 |
| Unique Plumbing Supplies Limited | Wholesale & retail | 2003 |
| Uniqueco Energy Ltd | Construction | 2023 |
| United Contractors Limited | Construction | 2017 |
| United Tool Distributors Limited | Wholesale & retail | 2001 |
| Unity Growth Limited | Professional & scientific | 2025 |
| Unity Home Care Ltd | Health & social care | 2024 |
| Unity Taekwondo Academy Ltd | Education | 2025 |
| Universal HE UK Limited | Education | 2025 |
| Universal Provenance Limited | Information & communication | 2009 |
| Universal Recruitment Solutions Limited | Administrative & support | 2001 |
| Universeal Product Agencies Limited | Wholesale & retail | 2008 |
| Unscripted Voices Limited | Information & communication | 2025 |
| Unspice Ltd | Hospitality | 2018 |
| Unsted Design Ltd | Professional & scientific | 2012 |
| UP & Running (Southampton) Limited | Wholesale & retail | 2008 |
| UP Developments Ltd | Construction | 2024 |
| UP Supported Living Services Ltd | Health & social care | 2024 |
| Uppcy Ltd | Wholesale & retail | 2021 |
| Upper Limb Orthopaedics Limited | Health & social care | 2011 |
| Uppercut Deluxe Co Limited | Wholesale & retail | 2016 |
| Uppz Ltd | Real estate | 2020 |
| Uptons of Bassett Limited | Wholesale & retail | 2003 |
| Urban Eden Beauty Salon Ltd | Other services | 2024 |
| Urban Salida Ltd | Information & communication | 2015 |
| Urban Symbiotics Limited | Professional & scientific | 2019 |
| Urbanforest Landscaping Ltd | Administrative & support | 2024 |
| Uretech Limited | Wholesale & retail | 2003 |
| Urquhart Development & Management Services Limited | Professional & scientific | 1996 |
| USE Natural Ltd | Wholesale & retail | 2009 |
| Utano Clinic Ltd | Health & social care | 2025 |
| Utili-Light Limited | Administrative & support | 2007 |
| Utilita Energy Limited | Energy | 2003 |
| Utilita Giving | Other services | 2022 |
| Utility Service Solutions Limited | Administrative & support | 2010 |
| UU School of International Education Limited | Education | 2026 |
| UX LED Research and Design Ltd | Information & communication | 2025 |
| V & F Sheet Metal Company Limited | Manufacturing | 1986 |
| V Hill Contracting Limited | Agriculture & fishing | 2004 |
| V Nitu Limited | Transport & logistics | 2019 |
| V&J Medi-Dent (PVT) Limited | Other services | 2024 |
| V-Productions Limited | Information & communication | 2025 |
| VA Alliance Holdings Ltd | Financial services | 2026 |
| VA Alliance LLP | | 2026 |
| Vacant Life Ltd | Professional & scientific | 2007 |
| Vale & Anderson Ltd | Professional & scientific | 2011 |
| Valley Knights Childcare Limited | Health & social care | 2025 |
| Valley Park Home Improvements Ltd | Other services | 2016 |
| Valsheda Estates Limited | Wholesale & retail | 2023 |
| Valvona Limited | Manufacturing | 2023 |
| Van Hage & Company Limited | Wholesale & retail | 1995 |
| Vanchiran Ltd | Transport & logistics | 2025 |
| Vandervelde Radiology Limited | Health & social care | 2014 |
| Vane Trans Ltd | Transport & logistics | 2019 |
| Vankru Cycling Limited | Other services | 2023 |
| Vantec Limited | Information & communication | 2000 |
| Vasileiou Associates Ltd | Health & social care | 2017 |
| Vastude Ltd | Professional & scientific | 2025 |
| Vaultage Media Ltd | Information & communication | 2020 |
| Vaultage Properties Ltd | Real estate | 2016 |
| Vaulted Networks Ltd | Information & communication | 2016 |
| Vaxigo Ltd | Information & communication | 2026 |
| VBR Property Limited | Real estate | 2020 |
| Vector Contracts Ltd | Education | 2024 |
| Veera Bhadra Limited | Health & social care | 2023 |
| Vehicle Preparation Services Limited | Manufacturing | 2004 |
| Vela Studio Ltd | Professional & scientific | 2026 |
| Velmore Community Association | Other services | 2011 |
| Velocity Technologies Ltd | Information & communication | 2020 |
| Ventura Kitchens Limited | Construction | 2014 |
| Venture Advisory (Southern) Ltd | Professional & scientific | 2024 |
| Venture Projects Hampshire Limited | Financial services | 2016 |
| Venture Properties (Newbury) Limited | Real estate | 2016 |
| Ventureclo Ltd | Wholesale & retail | 2025 |
| Vergo Holdings Limited | Financial services | 2020 |
| Vermento Ltd | Construction | 2023 |
| Vertex Apps & Media Ltd | Information & communication | 2026 |
| Verudatus Limited | Administrative & support | 2021 |
| Verve Accounting Limited | Professional & scientific | 2012 |
| VFS (Southampton) Limited | Manufacturing | 1995 |
| VGI Management Ltd | Administrative & support | 2003 |
| Viamad Systems Ltd | Administrative & support | 2023 |
| Vibe Enterprises Ltd | Real estate | 2014 |
| Vicjah Consult Ltd | Wholesale & retail | 2025 |
| Victortech Limited | Information & communication | 2017 |
| Victory Planning Services Limited | Financial services | 2013 |
| Victory Transport Solutions Limited | Transport & logistics | 2023 |
| Vida Bros Studios Limited | Information & communication | 2025 |
| Vida Dentistry Limited | Health & social care | 2015 |
| Vida Holding Limited | Financial services | 2022 |
| VIDERE66 Ltd | Professional & scientific | 2025 |
| Vietnam Nails Limited | Other services | 2009 |
| Vieva Healthcare Services Limited | Health & social care | 2024 |
| VII Management Limited | Arts & recreation | 2012 |
| Village Freeholders Ltd | Professional & scientific | 2014 |
| Vincent-Bradley Homes Ltd | Construction | 2018 |
| Violem Limited | Professional & scientific | 2026 |
| VIP Cutss Limited | Other services | 2024 |