| Waterglow Plumbing ,Heating and GAS Ltd | Other services | 2020 |
| Watson Contracting Limited | Agriculture & fishing | 2011 |
| Wavecrest Media Ltd | Professional & scientific | 2025 |
| WDG Inn Limited | Hospitality | 2010 |
| Wedding Intelligence Limited | Extraterritorial | 2011 |
| Welham Estates Lettings Limited | Real estate | 2003 |
| Wellco Heating Limited | Construction | 2023 |
| Wellsstore Ltd | Transport & logistics | 2025 |
| Wendy House Holdings Limited | Financial services | 2015 |
| Wesleyvale Limited | Hospitality | 1975 |
| West Court Residents' Association Limited | Households | 1970 |
| West Way 1963 Limited | Extraterritorial | 2014 |
| Wheeler Antiques Limited | Wholesale & retail | 2016 |
| Wheeler Auctions Limited | Wholesale & retail | 2023 |
| While Loop Limited | Information & communication | 2024 |
| White Dragon Training Ltd | Education | 2023 |
| White Lighting Limited | Arts & recreation | 2023 |
| White Lightning Limited | Arts & recreation | 2018 |
| White Park Properties Limited | Administrative & support | 2003 |
| White Space Creative Ltd | Manufacturing | 2004 |
| Whitecroft Cyber Advisory Limited | Professional & scientific | 2024 |
| Whitehawk Road | Financial services | 2020 |
| Whitney Leggatt Limited | Information & communication | 2004 |
| Whizzbang Limited | Information & communication | 2004 |
| WHY Go Digital Ltd | Information & communication | 2014 |
| Wibwob Limited | Information & communication | 2026 |
| Wild Bill Promotions Ltd | Extraterritorial | 2017 |
| Wild Country Organics Ltd | Agriculture & fishing | 2010 |
| Wild Spirit Sportswear Ltd | Wholesale & retail | 2024 |
| Wilkins Food (Harlow) Limited | Wholesale & retail | 2012 |
| William Court Residents Association Limited | Households | 1982 |
| Willington Green Limited | Professional & scientific | 2013 |
| Willow City Holdings Limited | Real estate | 2025 |
| Willow HR Limited | Administrative & support | 2013 |
| Willow Securities Limited | Real estate | 1992 |
| Willowcity Estates Limited | Construction | 1963 |
| Wimbridge Properties Ltd | Real estate | 2025 |
| Windfall Trustee Limited | Extraterritorial | 2025 |
| Windmill Car and Commercials Limited | Wholesale & retail | 2009 |
| Wingsuited Ltd | Professional & scientific | 2020 |
| Winiecki Associates Ltd | Professional & scientific | 2010 |
| Winter Izzard Homes Ltd | Construction | 2024 |
| Wirewell Electronic Services Limited | Manufacturing | 2000 |
| Wisbridge Developments Limited | Financial services | 2006 |
| Wisbridge Holdings Limited | Real estate | 2006 |
| Wise Accountancy Solutions Ltd | Professional & scientific | 2024 |
| With Intention Consulting Ltd | Professional & scientific | 2026 |
| Wittick Building Ltd | Construction | 2011 |
| Wocigol Limited | Manufacturing | 2017 |
| Wood DE Lastic Properties LLP | | 2023 |
| Wood Grill Group Ltd | Hospitality | 2022 |
| Woodford Group Limited | Administrative & support | 2024 |
| Woodford Holdings Limited | Professional & scientific | 1999 |
| Woodland Grange Management Limited | Real estate | 2008 |
| Woolpack Way Company Limited | Extraterritorial | 2003 |
| Woolsgrove Court Residents Management Company Limited | Households | 1996 |
| Worksop Industrial Transport Ltd | Financial services | 2020 |
| Worlds END Productions (London) Ltd | Arts & recreation | 2014 |
| Worn Bristle Studio Limited | Other services | 2024 |
| Wrestleraffles Ltd | Arts & recreation | 2025 |
| Wrights Mower Centre Limited | Administrative & support | 2001 |
| Wtfcpgw Ltd | Arts & recreation | 2012 |
| X-Scapes Ltd | Administrative & support | 2015 |
| Xebiro Limited | Information & communication | 2017 |
| Xgaming UK Ltd | Wholesale & retail | 2025 |
| Xorta Consultancy Ltd | Professional & scientific | 2025 |
| XTS UK Limited | Manufacturing | 2009 |
| Y Garn Ltd | Information & communication | 2011 |
| Yindee Thai Ltd. | Hospitality | 2009 |
| Yogafit Retreats Ltd | Administrative & support | 2017 |
| Yomatcha Ltd | Financial services | 2015 |
| Your Local Mechanics Limited | Wholesale & retail | 2026 |
| Z-Pulse Ltd | Professional & scientific | 2024 |
| Zaidan Cars Ltd | Wholesale & retail | 2018 |
| Zairai Elite Drive Ltd | Education | 2025 |
| Zantiks Limited | Manufacturing | 2014 |
| Zeevou Ltd | Information & communication | 2019 |
| Zenamed Limited | Health & social care | 2010 |
| Ziconix Ltd | Information & communication | 2007 |
| Zion Ambassadors Global Ministry Inc Limited | Administrative & support | 2024 |
| ZKS Aylesbury Limited | Arts & recreation | 2019 |
| ZKS Billing Limited | Professional & scientific | 2007 |
| ZKS Training Limited | Arts & recreation | 2022 |
| ZKS Watford Limited | Financial services | 2019 |
| ZR Total Web Solutions Ltd | Information & communication | 2024 |
| Élan Aesthetics Limited | Other services | 2025 |