| Tyson Hall Developments Ltd | Real estate | 2026 |
| UK Energy Storage Services Limited | Energy | 2016 |
| UK Solar (Hartwell) LLP | | 2014 |
| UK Solar (Lower Newton) LLP | | 2014 |
| UK Temporary Works Design Ltd | Professional & scientific | 2021 |
| United Travel Club Ltd | Administrative & support | 2015 |
| Unlimited PI Ltd | Information & communication | 2019 |
| VAL and RAY Ltd | Professional & scientific | 2013 |
| Valkyrie Land and Development Limited | Real estate | 2019 |
| Valkyrie Project Management Limited | Professional & scientific | 2025 |
| Valmont 2025 Ltd | Arts & recreation | 2025 |
| Vast Creative Publicity Limited | Administrative & support | 2000 |
| Vast PR Ltd | Extraterritorial | 2011 |
| VBR Watford Ltd | Wholesale & retail | 2026 |
| Vectr Limited | Wholesale & retail | 2025 |
| Veespark Electrics Ltd | Energy | 2022 |
| Venue Queen Ltd. | Professional & scientific | 2016 |
| Versa Engineering Group Limited | Manufacturing | 2021 |
| Versacoat Limited | Manufacturing | 2009 |
| Victoria Lench Ltd | Professional & scientific | 2018 |
| Vintage Angels Ltd | Extraterritorial | 2014 |
| VISION4 Accountancy & Tax Solutions Limited | Professional & scientific | 2015 |
| Viste Apparel Ltd | Wholesale & retail | 2024 |
| Viveur Ltd | Professional & scientific | 2021 |
| VJM Property Solutions Limited | Real estate | 2015 |
| Vooshama Ltd | Hospitality | 2024 |
| VSM Ventures Ltd. | Real estate | 2020 |
| W&J Donald Services Ltd | Construction | 2014 |
| Walter Family Investments Limited | Real estate | 2016 |
| Warm Porridge Consulting Limited | Information & communication | 2015 |
| Waterfall Photo Booth Limited | Administrative & support | 2024 |
| Waterfall Wedding Decor Ltd | Administrative & support | 2018 |
| Watford Paving & Asphalting Ltd | Administrative & support | 2023 |
| Watford Recruitment Limited | Administrative & support | 2026 |
| Watford Residential & Commercial Signs Ltd | Professional & scientific | 2014 |
| Wealthcare Independent Financial Planning Limited | Financial services | 2006 |
| Wealthcare Independent Investment Planning Limited | Extraterritorial | 2006 |
| Wear Point Wind Limited | Energy | 2012 |
| Weare Education Ltd | Education | 2022 |
| WEM Together Ltd | Arts & recreation | 2025 |
| West 13 Ltd | Hospitality | 2026 |
| West Hertfordshire Swim School LLP | | 2014 |
| Westcare KL Ltd | Real estate | 2013 |
| Westerhill Properties Ltd | Real estate | 2022 |
| Westfields Homes (Denton) Limited | Construction | 2017 |
| Westfields Homes (Edmonton) Ltd | Construction | 2021 |
| Westfields Homes (Figaro) Ltd | Construction | 2018 |
| Westfields Homes (Hatfield Road) Ltd | Construction | 2023 |
| Westfields Homes (Nascot Street) Limited | Construction | 2017 |
| Westfields Homes (Tippendell) Limited | Construction | 2023 |
| Westfields Homes (Windrush) Limited | Real estate | 2025 |
| Weston Analytics Limited | Information & communication | 2018 |
| Weston Gate Residents Management Company Limited | Households | 2023 |
| Westport Energy Storage Limited | Energy | 2024 |
| Wetherall Property Services Limited | Other services | 2026 |
| White Horse PUB Chorleywood Limited | Hospitality | 2022 |
| White Oak Dental Ltd | Health & social care | 2018 |
| White Rock Business Park Limited | Real estate | 2008 |
| Whittlesey Limited | Energy | 2013 |
| Wilcox Enterprises Ltd | Wholesale & retail | 2009 |
| Williams Windows DG Ltd | Construction | 2015 |
| Wind Assets LLP | | 2009 |
| Wind Energy Systems Limited | Extraterritorial | 1996 |
| Wind Farm Holdings Limited | Professional & scientific | 2003 |
| Winking Hill Energy Storage Limited | Energy | 2024 |
| Winsham IT Ltd | Information & communication | 2015 |
| Withers & Curling Limited | Real estate | 2025 |
| Within Corporation Ltd | Education | 2022 |
| Wiya Express Ltd | Wholesale & retail | 2025 |
| WJ Groundwater Limited | Construction | 1981 |
| WJ Management Limited | Financial services | 1997 |
| Woodburn Holdings Ltd | Real estate | 2020 |
| WORKZ4U App Ltd | Information & communication | 2026 |
| Wpip Developments Limited | Real estate | 2024 |
| Wryde Croft Wind Farm Limited | Energy | 2004 |
| WY Pinner Road Limited | Administrative & support | 2018 |
| Xrosscolab Ltd | Information & communication | 2019 |
| Xtnd Report Ltd | Professional & scientific | 2021 |
| Xtura Limited | Professional & scientific | 2022 |
| York & Union Limited | Wholesale & retail | 2013 |
| Yorkshire Hydropower Holdings Limited | Energy | 2017 |
| Yorkshire Hydropower Limited | Energy | 2014 |
| Your Home Rewire Ltd | Construction | 2021 |
| Your UNI Solutions Ltd | Information & communication | 2025 |
| Zandes Group Ltd | Other services | 2023 |
| ZC Consulting Limited | Professional & scientific | 2012 |
| Zeasy Ltd | Other services | 2015 |
| Zerny Investment Company Limited | Administrative & support | 2014 |
| ZOE Smith Legal Services Limited | Professional & scientific | 2023 |