| Whitelinenhousekeeping Ltd | Administrative & support | 2026 |
| Whitestone Building Solutions Limited | Construction | 2020 |
| Whitestone Group Holdings Limited | Financial services | 2023 |
| Whitestone Mechanical and Electrical Limited | Construction | 2018 |
| Whithersea Ltd | Manufacturing | 2019 |
| Whole Building Services WBS Limited | Construction | 2009 |
| Wholesalexpressions Ltd | Wholesale & retail | 2023 |
| Whopjet Concierge Limited | Administrative & support | 2025 |
| Whybrook Developments Limited | Construction | 2013 |
| Whybrook Limited | Construction | 2011 |
| Wick Solutions Limited | Transport & logistics | 2017 |
| Wickland (Holdings) Limited | Real estate | 1981 |
| Wicm Ltd | Professional & scientific | 2025 |
| Wide-Scope Services Limited | Administrative & support | 1993 |
| Wield Group Ltd | Information & communication | 2023 |
| Wiese Limited | Professional & scientific | 2026 |
| Wigginit UK Ltd | Wholesale & retail | 2024 |
| Wild Frog Limited | Wholesale & retail | 2011 |
| Wild Reveries Ltd | Wholesale & retail | 2023 |
| Wild Wings Limited | Hospitality | 2023 |
| Wilding Sound Limited | Arts & recreation | 2009 |
| Will Writing Company Ltd | Professional & scientific | 2024 |
| William Claridge Limited | Real estate | 1964 |
| William Cleaning Limited | Administrative & support | 2024 |
| William J.Gowar & Company Limited | Manufacturing | 1950 |
| William Lewis Fitted Furniture Ltd | Other services | 2023 |
| William Rose Highams Park Ltd | Real estate | 2021 |
| William Rose Woodford Ltd | Real estate | 2018 |
| Williams Dwellings Ltd | Real estate | 2022 |
| Williams Legal Limited | Professional & scientific | 2018 |
| Willis & FOX Ltd | Households | 2021 |
| Willmulholland Investments Ltd | Financial services | 2020 |
| Willmulholland Limited | Professional & scientific | 2016 |
| Willow Capital Solutions Limited | Real estate | 2026 |
| Willow Garden and Home Services Ltd | Administrative & support | 2026 |
| Willow Quintan Limited | Wholesale & retail | 2017 |
| Willow Studio Limited | Real estate | 2022 |
| Willow Way Residents Association Ltd | Households | 2024 |
| Willowbrew Limited | Hospitality | 2026 |
| Willows Food & Wine Ltd | Extraterritorial | 2015 |
| Wilor Ltd | Education | 2017 |
| Wilson Healthcare Services Ltd | Administrative & support | 2022 |
| Wilson Wheels Ltd | Wholesale & retail | 2025 |
| Wiltons Electrical Contractors Limited | Construction | 2015 |
| Wimax Ltd | Wholesale & retail | 2023 |
| Wimbledon Properties Limited | Real estate | 2023 |
| WIN a London Home Ltd | Information & communication | 2018 |
| WIN a Van Limited | Wholesale & retail | 2015 |
| Winchester Hardwood Flooring Limited | Wholesale & retail | 2003 |
| Winchester-Fraser Limited | Professional & scientific | 1999 |
| Windmill Energy Limited | Wholesale & retail | 2021 |
| Windo Ltd | Professional & scientific | 2025 |
| Window Fitters Cladding Ltd | Construction | 2025 |
| Window Tech Trade Limited | Administrative & support | 2002 |
| Wine Affairs Limited | Wholesale & retail | 2018 |
| Wing Hing Bento Ltd | Hospitality | 2025 |
| Wing WAH Food Ltd | Hospitality | 2019 |
| Wingle-Tye Pre-School Ltd. | Education | 2000 |
| Wings Asset Management Limited | Real estate | 2020 |
| Wingz N DAT Ltd | Hospitality | 2019 |
| Winko Fightwear Ltd | Wholesale & retail | 2025 |
| Winners-R-Grinners Ltd | Construction | 2020 |
| Winpro Enterprises Ltd | Construction | 2024 |
| Winston Recruitment Limited | Professional & scientific | 2018 |
| Wintermute Services Limited | Real estate | 2016 |
| Winward Finance Ltd | Professional & scientific | 2026 |
| Wipeberg Ltd | Information & communication | 2022 |
| Wired & Wireless Ltd | Information & communication | 2010 |
| Wirran Property Company Limited | Professional & scientific | 2006 |
| Wiscaff Ltd | Other services | 2025 |
| Wisdon Consultancy Ltd | Information & communication | 2025 |
| Wise Compliance Ltd | Professional & scientific | 2013 |
| Wise Educational Centre Ltd | Education | 2025 |
| Wise Move MAN & Van Services Ltd | Transport & logistics | 2018 |
| Wise UK Properties Ltd | Real estate | 2025 |
| Wiselectric Ltd | Construction | 2013 |
| Wish Mania Limited | Hospitality | 2019 |
| Wish Upon a Calligraphy Ltd | Wholesale & retail | 2021 |
| Wishes Caterers Ltd | Other services | 2023 |
| Wishes Foods Ltd | Wholesale & retail | 2023 |
| Wissper Brand Management Limited | Information & communication | 2019 |
| Witel Global Ltd | Wholesale & retail | 2014 |
| Wivenhoe Crown Ltd | Hospitality | 2026 |
| Wivenhoe Furniture Rentals Limited | Other services | 2016 |
| Wixdek IT Ltd | Wholesale & retail | 2016 |
| WIZ Recruitment Ltd | Administrative & support | 2022 |
| Wizard Car Repairs Ltd | Wholesale & retail | 2016 |
| Wize Limited | Wholesale & retail | 2025 |
| Wizemove Limited | Real estate | 2023 |
| WLA Apex Ltd | Construction | 2025 |
| WLB Consultancy Services Limited | Professional & scientific | 2021 |
| WLB Consultants LLP | | 2019 |
| WMD Properties Limited | Real estate | 2020 |
| WOJ & AGA Ltd | Real estate | 2023 |
| Wojtek Property Maintenance Ltd | Construction | 2026 |
| WOK HUT Ltd | Hospitality | 2025 |
| Wolcor Holdings Limited | Financial services | 2023 |
| Wolexus Ltd | Wholesale & retail | 2018 |
| Wolf Carpentry Ltd | Manufacturing | 2016 |
| Women That Program Ltd | Information & communication | 2024 |