| WEE 3 Limited | Professional & scientific | 1996 |
| Weldon Court Residents Ltd | Households | 2008 |
| Well Managed Accounts Limited | Professional & scientific | 2004 |
| Welwyn Hatfield Tamil School Ltd | Education | 2025 |
| Wenhedge Limited | Construction | 1998 |
| Wenlock House (Enfield) RTM Company Limited | Real estate | 2020 |
| West London Plastics Limited | Real estate | 1973 |
| West Seventy Nine Limited | Wholesale & retail | 2016 |
| Westall Close Management Limited | Households | 1993 |
| Westminster Refining Limited | Water & waste | 2009 |
| Westside Maintenance Limited | Construction | 2016 |
| WFK Property Limited | Real estate | 2021 |
| White BAT Ltd | Information & communication | 2010 |
| White Canvas Cubed Ltd | Professional & scientific | 2011 |
| White Iris Management Ltd | Manufacturing | 2022 |
| Whitehall Finance Limited | Financial services | 2015 |
| WI & WA Limited | Households | 2022 |
| Wiba Generators Ltd | Administrative & support | 2022 |
| Widesight Ltd | Professional & scientific | 2016 |
| Wightman Road Tyres Limited | Wholesale & retail | 2020 |
| Wild MAN Games Ltd | Information & communication | 2024 |
| Wildstar Media Ltd | Information & communication | 2022 |
| William Harris Bacon Holdings 1961 Limited | Financial services | 1961 |
| William Harris Bacon NO. 2 Limited | Real estate | 2018 |
| Willoughby Place Limited | Health & social care | 1997 |
| Willoughby Place Piedmont Road Limited | Other services | 2021 |
| Wimbledon Debentures Only Limited | Administrative & support | 2024 |
| Wincey Developments Limited | Construction | 2022 |
| Windmill Rise (Enfield) Residents Association Limited | Households | 1998 |
| Windmore Hall Ltd | Households | 1991 |
| Window Collective Ltd | Construction | 2024 |
| Windsor Lock and Repair Ltd | Financial services | 2022 |
| Wines With Attitude Limited | Wholesale & retail | 2014 |
| Wintam Limited | Information & communication | 2019 |
| Wire Holdings Limited | Financial services | 2020 |
| Wireguard Limited | Information & communication | 2023 |
| Wisdom Equestrian Limited | Wholesale & retail | 2019 |
| WISDOM67 Investments Ltd | Real estate | 2023 |
| Wise Engineering Design & Survey Limited | Professional & scientific | 2018 |
| Wise Hill Homes Limited | Real estate | 2019 |
| Wise Hill Management Ltd | Households | 2025 |
| Wispa’S RAW Ltd | Manufacturing | 2024 |
| Wixamtree 2 Management Limited | Households | 2025 |
| WJA Surveyors Limited | Professional & scientific | 2018 |
| WLB Retail & Commerce Ltd | Wholesale & retail | 2019 |
| WM Fieldmouse Limited | Other services | 2025 |
| Wnts Corporation Ltd | Administrative & support | 2004 |
| Wolfe House Limited | Health & social care | 2006 |
| Wonderland Show Ltd | Wholesale & retail | 2024 |
| Wood Green High Road Management Limited | Households | 2021 |
| Woodcote Grove Management Limited | Households | 2021 |
| Woodland Wanderers Montessori Forest School Rickmansworth Ltd | Health & social care | 2025 |
| Workshopwise Limited | Information & communication | 2012 |
| World of Windows and Doors Limited | Manufacturing | 1994 |
| World Property Services Limited | Real estate | 1998 |
| Worldwide Recovery Systems Limited | Manufacturing | 1994 |
| Wormalds Limited | Construction | 2025 |
| Worth Using Limited | Other services | 2007 |
| WOS Properties Ltd | Real estate | 2020 |
| WOW Brow Nails Brows Lashes Ltd | Other services | 2022 |
| WPK Trading Ltd | Wholesale & retail | 2021 |
| Wreathestate Limited | Real estate | 2019 |
| Wren Building (London) Limited | Construction | 2014 |
| Wrightpoint Estates Limited | Real estate | 2007 |
| Wryland Estates Limited | Real estate | 2000 |
| Wulstan Park Management Limited | Households | 1998 |
| Wwdd Group Limited | Wholesale & retail | 2025 |
| Www.Rentwithus.Online Limited | Real estate | 2017 |
| X & Y Engineering Service Limited | Construction | 2011 |
| X-Aces Consultancy Limited | Information & communication | 2013 |
| Xandria Fragrance Limited | Manufacturing | 2024 |
| Xenagetis Consulting Limited | Administrative & support | 2005 |
| Xenios Investments Limited | Real estate | 2007 |
| Xenomania Productions Limited | Information & communication | 2000 |
| Xenomania Songs Limited | Information & communication | 1999 |
| Xenomania UK Limited | Information & communication | 2018 |
| Xenomania US Limited | Information & communication | 2018 |
| Xenosongs Three Limited | Arts & recreation | 2012 |
| Xenosongs TOO Limited | Information & communication | 2006 |
| Xiacademy Ltd | Arts & recreation | 2025 |
| Xstrade Limited | Water & waste | 2014 |
| Xtale Ltd | Professional & scientific | 2025 |
| Xtech Electrical Ltd. | Construction | 2014 |
| Xtendium Limited | Professional & scientific | 2014 |
| Y & J Group Ltd | Real estate | 2024 |
| Y2 Consulting Limited | Real estate | 2026 |
| YAN MAR Logistic Ltd | Transport & logistics | 2024 |
| YAY Clinic Ltd | Other services | 2022 |
| YAY Hair Ltd | Hospitality | 2025 |
| YE Olde Rose and Crown Theatre PUB Limited | Hospitality | 2008 |
| Yellow & Blue Productions Limited | Information & communication | 2011 |
| Yellow Door Consulting Ltd | Information & communication | 2015 |
| Yellow Tuesday Ltd | Administrative & support | 2015 |
| Yengin Ltd | Wholesale & retail | 2018 |
| Yeti London Welfare Foundation Limited | Other services | 1996 |
| YGE Holdings Ltd | Financial services | 2025 |
| YGE Properties Ltd | Real estate | 2025 |
| Ying Industries Limited | Professional & scientific | 2002 |
| Ying-Eds Limited | Professional & scientific | 2008 |
| Yogavani Ltd | Arts & recreation | 2010 |