| White Hart (Hertford) Developments Ltd | Real estate | 2009 |
| White Hart Developments (Ware) Limited | Real estate | 2025 |
| White Horse Close Management Company Limited | Households | 2018 |
| White Horse Mews (Wadesmill) Management Company Limited | Real estate | 2024 |
| White House 3 Holdings Ltd | Financial services | 2026 |
| White House Mortgage Services Ltd | Administrative & support | 2026 |
| White Oak Carpentry and Building Ltd | Construction | 2021 |
| Whiteapproach Ltd | Hospitality | 2026 |
| Whitegla Ltd | Extraterritorial | 2021 |
| Whitehouse Asset Investment Ltd | Real estate | 2024 |
| Whitehouse Real Estate Group Limited | Financial services | 2023 |
| Whitehouse Real Estate Management Ltd | Administrative & support | 2024 |
| Whitehouse Serviced Accommodation Ltd | Real estate | 2024 |
| Whoison Ltd | Information & communication | 2026 |
| WHY Media Ltd | Professional & scientific | 2010 |
| Willbeck Investments Ltd | Real estate | 2019 |
| William Fountain Limited | Manufacturing | 1985 |
| William Long Limited | Information & communication | 2016 |
| Willisrail Ltd | Administrative & support | 2014 |
| Willow Bough Yard Management Limited | Households | 2015 |
| Willow People Solutions Limited | Administrative & support | 2026 |
| Willow Wood Day Nurseries Ltd | Other services | 2014 |
| Willowmead Developments Ltd | Construction | 2011 |
| Willowmead Terrace Limited | Real estate | 2024 |
| Wills Wheels Ltd | Wholesale & retail | 2025 |
| Wiltonsign Properties Limited | Financial services | 1997 |
| Winch Consultancy Services Limited | Wholesale & retail | 2023 |
| Window Maintenance Solutions Ltd | Construction | 2022 |
| Windowman & Sons Limited | Construction | 2005 |
| Windrush Motorsport Ltd | Arts & recreation | 2018 |
| Windsor House Management Company Limited | Households | 1994 |
| Wines Today Limited | Wholesale & retail | 2025 |
| Wingate Construction Limited | Administrative & support | 1995 |
| Winpost Limited | Real estate | 1988 |
| Winsor Garages Limited | Administrative & support | 2003 |
| Wise Skies Ltd | Wholesale & retail | 2020 |
| Wisegrove Limited | Other services | 1984 |
| Wishing Tree Creatives Ltd | Information & communication | 2023 |
| With Lucy Joanne Limited | Administrative & support | 2026 |
| Wjtn Ltd | Professional & scientific | 2025 |
| WL Admin Ltd | Financial services | 2022 |
| WL Donations Ltd | Public administration | 2021 |
| WL Operations Limited | Professional & scientific | 2021 |
| Wolf and Lamb Limited | Hospitality | 2014 |
| Wonderfilm Pictures Limited | Wholesale & retail | 2016 |
| Wood Decoration Services Ltd | Construction | 2025 |
| Wood Grave Memorials Ltd | Manufacturing | 2020 |
| Woodcraft Shutters Limited | Construction | 2019 |
| Woodhall Estate Management Limited | Real estate | 2018 |
| Woodhall Estate Nominees (One) Limited | Financial services | 2018 |
| Woodhall Estate Nominees (Two) Limited | Financial services | 2018 |
| Woodland View (Stapleford) Management Company Limited | Real estate | 2020 |
| Woodlands Tree Nursery Ltd | Wholesale & retail | 2024 |
| Woodman Path (Hainault) Management Company Limited | Households | 1989 |
| Woodwood London Limited | Professional & scientific | 2013 |
| Woolaston House Private Medical Chambers Ltd | Health & social care | 2008 |
| Woolmers Park Farm Limited | Agriculture & fishing | 1997 |
| Workmans Recruitment Limited | Administrative & support | 2023 |
| World Online Transactional Analysis Association CIC | Professional & scientific | 2020 |
| World Seniors Darts Ltd | Administrative & support | 2021 |
| Worldwide Property Consultants Limited | Professional & scientific | 2014 |
| WP Recovery Ltd | Wholesale & retail | 2013 |
| Wrecktify Ltd | Wholesale & retail | 2024 |
| Wright Choice Limited | Professional & scientific | 2005 |
| Wrights Design and Build Ltd | Professional & scientific | 2018 |
| WRN Construction Ltd | Construction | 2023 |
| WRN Property Limited | Real estate | 2024 |
| Wrongfuelquickfit Ltd | Water & waste | 2026 |
| Wross Services Limited | Hospitality | 2021 |
| WW WE CRE8 Ltd | Professional & scientific | 2025 |
| XBX Trading Ltd | Wholesale & retail | 2021 |
| Xfactor Motorcycles Ltd | Wholesale & retail | 2025 |
| Xporter Ltd | Wholesale & retail | 2022 |
| Xscenx Ltd | Other services | 2023 |
| XYZ Driving Services Ltd | Transport & logistics | 2026 |
| Xzavier Limited | Information & communication | 2016 |
| Yardarm Club Limited(The) | Hospitality | 1962 |
| Yellow Blue Playground Ltd | Professional & scientific | 2017 |
| YEW Commercial Finance Limited | Professional & scientific | 2024 |
| YFR Ltd | Professional & scientific | 2009 |
| Yfrh Ltd | Professional & scientific | 2019 |
| York Place (Dagenham) Management Company Limited | Households | 1987 |
| YOU Again Aesthetics Limited | Other services | 2018 |
| Youngs Mews Residents Limited | Administrative & support | 2003 |
| Your Wise Creative Limited | Professional & scientific | 2010 |
| Yourqs Consultancy Limited | Financial services | 2014 |
| Yovita Healthcare Ltd | Health & social care | 2015 |
| Yovita Ltd | Construction | 2014 |
| YRS Potters Bar Limited | Construction | 2015 |
| YWB Food Wycombe Ltd | Hospitality | 2025 |
| Z&V Properties Limited | Construction | 2020 |
| ZAR Management and Consultancy Ltd | Professional & scientific | 2024 |
| Zefco Limited | Hospitality | 2019 |
| Zekana Limited | Other services | 2011 |
| Zendm Limited | Manufacturing | 2019 |
| Zenith Herts Limited | Arts & recreation | 2024 |
| Zenon Consulting Engineers Limited | Professional & scientific | 2017 |
| ZERO21 Brands Limited | Wholesale & retail | 2018 |
| ZERO21 Holdings Limited | Financial services | 2023 |
| Zerody Designs Limited | Administrative & support | 2020 |