| Uidentify Limited | Information & communication | 2015 |
| UK Bobo Ltd | Transport & logistics | 2017 |
| UK Stock Car Parts Ltd | Wholesale & retail | 2025 |
| Ukhhm C.I.C. | Education | 2023 |
| Ukos Projects Limited | Real estate | 2015 |
| Ultimate Dapur Experience (UK) Limited | Hospitality | 2013 |
| Ultra KBB Ltd | Construction | 2020 |
| Unania Ventures Limited | Agriculture & fishing | 2025 |
| Unbranded Media Limited | Information & communication | 2026 |
| Underrated Capital Ltd | Professional & scientific | 2025 |
| Uniamaze Limited | Wholesale & retail | 2024 |
| Unicut Precision Limited | Professional & scientific | 1992 |
| Unifinancial Solutions Limited | Professional & scientific | 2024 |
| Unique Surfaces Plus Limited | Construction | 2017 |
| United Capital Finance Limited | Financial services | 2016 |
| United Dairy (Bishopsgate) Limited | Wholesale & retail | 1997 |
| Unity Morfeas Limited | Hospitality | 2025 |
| Universal Quality Professionals Ltd | Professional & scientific | 2011 |
| Univox Audio Limited | Wholesale & retail | 2012 |
| Unlock - Youth Work Training Limited | Education | 2025 |
| Untypical Growth Limited | Professional & scientific | 2025 |
| Up.Aerial Limited | Professional & scientific | 2020 |
| Uplevel Consultancy Ltd | Professional & scientific | 2017 |
| Urself Beauty Space Ltd | Other services | 2023 |
| US Lifestyle Ltd | Arts & recreation | 2026 |
| Utiliconnect Ltd | Construction | 2018 |
| Uxlegal Limited | Information & communication | 2024 |
| V & T Holdings Limited | Extraterritorial | 2015 |
| V&E Limited | Hospitality | 2025 |
| V.Ita Services Ltd | Transport & logistics | 2026 |
| V.O.R. Services Limited | Manufacturing | 1986 |
| Vaisu Limited | Health & social care | 2020 |
| Vaital Ltd | Extraterritorial | 2025 |
| Valcare Ltd | Health & social care | 2014 |
| Valley Road Consulting Limited | Professional & scientific | 2014 |
| Value Flow Solutions Limited | Information & communication | 2016 |
| Van Duijn Transport Ltd | Transport & logistics | 2015 |
| Vape Jungle (Hertford) Limited | Wholesale & retail | 2016 |
| VCO Limited | Real estate | 2024 |
| Velaris Ltd | Construction | 2020 |
| Velemee Limited | Health & social care | 2023 |
| Veridien Consulting Partners Limited | Professional & scientific | 2024 |
| Vertical Transportation Solutions Ltd | Construction | 2014 |
| VIA World Logistics Ltd | Other services | 2017 |
| Viago Limited | Wholesale & retail | 2012 |
| Vibeside Music Management Ltd | Information & communication | 2023 |
| Victoria Imperial Limited | Wholesale & retail | 2021 |
| Victory Healthcare Limited | Health & social care | 2011 |
| Videoromeo Ltd | Information & communication | 2025 |
| Vigilant Proactive Limited | Information & communication | 2017 |
| Vigna Consulting Limited | Construction | 2022 |
| Vigour Fitness Group Ltd | Arts & recreation | 2021 |
| Vinada Property Investments Ltd | Real estate | 2018 |
| Vinada Services Ltd | Health & social care | 2011 |
| Vincent's Health and Fitness Limited | Arts & recreation | 2015 |
| Vintage Autocare Ltd | Wholesale & retail | 2019 |
| Vinzzenzio's Ltd | Wholesale & retail | 2011 |
| Virtual Works 360 Ltd | Wholesale & retail | 2017 |
| Virtualmediagroup Ltd | Professional & scientific | 2025 |
| Visionary Pictures Ltd | Information & communication | 2020 |
| Visual by Future Ltd | Information & communication | 2024 |
| Vita Financial Planning Ltd | Professional & scientific | 2013 |
| Vithane Managed Solutions Limited | Information & communication | 2001 |
| Vitobada Limited | Real estate | 2023 |
| Vkmack Limited | Professional & scientific | 2025 |
| VKR Trading Co Ltd | Wholesale & retail | 2024 |
| VM Survey Ltd | Professional & scientific | 2019 |
| VMS Building Ltd | Construction | 2022 |
| Vndr.Net Ltd | Information & communication | 2014 |
| Voice Services Limited | Information & communication | 1997 |
| Vokera Limited | Wholesale & retail | 1972 |
| Vora Finance Corporation Limited | Professional & scientific | 1981 |
| Vortech Food Machinery Limited | Wholesale & retail | 2012 |
| Vptp Limited | Construction | 2024 |
| VR Security Ltd | Information & communication | 2016 |
| VRD Solution Ltd | Administrative & support | 2012 |
| VRW Homes Limited | Real estate | 2024 |
| VSK Wholesale Ltd | Wholesale & retail | 2025 |
| VSL Group Ltd | Administrative & support | 2021 |
| VSL Networks Ltd | Information & communication | 2005 |
| VT Flow Plumbing & Heating Ltd | Construction | 2026 |
| Wadzie MFP Limited | Other services | 2015 |
| Waldegrave Road Limited | Real estate | 2008 |
| Walk the Line Pictures Limited | Information & communication | 2022 |
| Walk the Line Productions Limited | Arts & recreation | 2018 |
| Warboss Workshop Ltd | Wholesale & retail | 2026 |
| Ware Skips Limited | Water & waste | 2020 |
| Warmspark Building Services Ltd | Construction | 2023 |
| Washforcall Ltd | Administrative & support | 2014 |
| Water Consulting Worldwide Ltd | Professional & scientific | 2017 |
| Wayne Clark Electrical Limited | Construction | 2015 |
| WDL Electrical Ltd | Construction | 2021 |
| WE FIX Maintenance Ltd | Manufacturing | 2025 |
| Weimler Limited | Information & communication | 2020 |
| Welbrook LLP | | 2013 |
| Welland Consultancy Limited | Professional & scientific | 2015 |
| Welwyn (Mechanical) Services Limited | Administrative & support | 2008 |
| Welwyn and Hatfield Reusable Nappy Group CIC | Administrative & support | 2020 |
| Welwyn Brewery Limited | Manufacturing | 2022 |
| Welwyn Builders Ltd | Construction | 2026 |