| Western Investment Property Limited | Administrative & support | 2004 |
| Western Property Investments Limited | Real estate | 2006 |
| Westflor Holdings Limited | Professional & scientific | 1999 |
| Westland Trading Limited | Wholesale & retail | 2000 |
| Westmoreland Roofing Limited | Construction | 2004 |
| Westway Corporation Ltd | Administrative & support | 1998 |
| Westway Services Holdings (2010) Ltd. | Professional & scientific | 2008 |
| Westway Services Holdings (2014) Ltd | Professional & scientific | 2014 |
| Westwood Associates Limited | Information & communication | 1992 |
| Westzane Holding Limited | Financial services | 2022 |
| Weybridge Management Limited | Professional & scientific | 1989 |
| WHA Trading Limited | Wholesale & retail | 2003 |
| What IF Consultancy Limited | Professional & scientific | 2007 |
| White Cloud Development Limited | Information & communication | 2007 |
| White Spider Media Holdings Limited | Professional & scientific | 2022 |
| Whitefield Financial Services Limited | Financial services | 2004 |
| Whitegate Financial Services Limited | Financial services | 2005 |
| Whitelake Properties Limited | Hospitality | 1997 |
| Wholesome Spice Ltd | Hospitality | 2017 |
| Wholesum Limited | Wholesale & retail | 2023 |
| WIL FX Ltd | Arts & recreation | 2024 |
| Wilcroft Holdings Limited | Construction | 1964 |
| Wilcroft Investment Company Limited | Construction | 1963 |
| Wild Oaks Close Residents Management Limited | Real estate | 1991 |
| Wildcard Worldwide Ltd | Financial services | 2009 |
| Wildoo Limited | Administrative & support | 2001 |
| Wilking Ltd | Wholesale & retail | 2001 |
| Willan Pharm Limited | Health & social care | 2003 |
| William Grayburn Films Limited | Arts & recreation | 2007 |
| William Overstall Ltd | Arts & recreation | 2015 |
| William's Technical Services Limited | Extraterritorial | 1962 |
| Willowbrook Surveying Limited | Professional & scientific | 2007 |
| Willowhayne Management Number 2 Ltd | Households | 2004 |
| Wilman Marine Limited | Manufacturing | 1981 |
| Wilman Universal Group Limited | Manufacturing | 2002 |
| Wilson Electrical Limited | Construction | 2005 |
| Winchfield Investments Limited | Real estate | 2003 |
| Windcrest LP | | 2012 |
| Windermere Corporation Ltd | Administrative & support | 2004 |
| Winparks Management Limited | Real estate | 2005 |
| Winparks Practice Limited | Health & social care | 2007 |
| Winston Solutions Ltd | Administrative & support | 2017 |
| Winterfreeze Ltd | Construction | 1997 |
| Wispville Properties Limited | Construction | 2003 |
| Wlmg Limited | Wholesale & retail | 1996 |
| Wolfpak Ltd | Wholesale & retail | 2025 |
| Wolpertinger Limited | Arts & recreation | 2012 |
| Women’S Independence and Sustainable Equality (W.I.S.E) CIC | Other services | 2021 |
| Wonderdust Services Ltd | Information & communication | 2021 |
| Wood Floor Renovations (London) Limited | Construction | 2003 |
| Woodbrook Associates Limited | Real estate | 2003 |
| Woodland Pharmacy Ltd | Wholesale & retail | 2005 |
| Woodlands (Northwood) Freehold Company Ltd | Real estate | 2018 |
| Woodlands Grove Limited | Hospitality | 2003 |
| Woodtech Interiors Limited | Construction | 2005 |
| Woodthorpe Sales Limited | Wholesale & retail | 1976 |
| Woodview Court Residents Association (NO.2) Limited | Households | 1978 |
| Wooster's Mews Management Limited | Households | 1979 |
| World Leisure Developments Ltd. | Arts & recreation | 1996 |
| World Nodes Limited | Administrative & support | 2024 |
| Worldin Holding Ltd | Financial services | 2019 |
| Worldtrend Data Limited | Professional & scientific | 1990 |
| Worthing Properties Limited | Real estate | 2005 |
| Wotan Film Limited | Information & communication | 1997 |
| WR Property Funding Ltd | Professional & scientific | 2007 |
| Wright Barlow Limited | Professional & scientific | 2003 |
| Wright Gardens (Shepperton) Management Co Ltd | Extraterritorial | 1996 |
| Written Media Limited | Information & communication | 2007 |
| Wynn Interiors Limited | Construction | 2015 |
| Xamalo Ltd | Construction | 2021 |
| Xanthia Limited | Administrative & support | 1994 |
| Xcap Investments Ltd | Financial services | 2022 |
| Xcel 360 Ltd | Wholesale & retail | 2022 |
| XEC Limited | Transport & logistics | 2007 |
| Xenonbay Limited | Professional & scientific | 2019 |
| Xier Kangtai Pharma - Co. Limited | Other services | 2003 |
| Xnett Ltd | Information & communication | 2025 |
| Xphil Limited | Professional & scientific | 1946 |
| Xpress Accountancy Services Limited | Professional & scientific | 2003 |
| Xpress Locksmiths 24H Ltd | Professional & scientific | 2026 |
| Xylophone Design Limited | Information & communication | 2011 |
| YA Project Consulting Limited | Information & communication | 2012 |
| Yadana Limited | Real estate | 2002 |
| Yamato Digital Ltd | Information & communication | 2022 |
| Yangdu-Duyang International Ltd | Administrative & support | 2017 |
| Yaqootaalys Gallery Ltd | Wholesale & retail | 2017 |
| Yardcroft Limited | Households | 1995 |
| Yazafa Limited | Wholesale & retail | 2003 |
| YCN Investments Limited | Real estate | 2020 |
| Yeomans & Partners Limited | Wholesale & retail | 1945 |
| Yerevan Engineering Ltd | Administrative & support | 1998 |
| YES OUI SI Ltd | Construction | 1997 |
| YEW Tree Care Limited | Health & social care | 2001 |
| YG Eaton & Co Limited | Professional & scientific | 2002 |
| Yiannimize Group Limited | Other services | 2021 |
| Yoga Yatra Studio Ltd | Other services | 2016 |
| Yomans (London) Limited | Real estate | 1965 |
| Yoop Limited | Professional & scientific | 2014 |
| Youmeus Design Limited | Administrative & support | 2003 |
| Yummi House Ltd | Hospitality | 2024 |