| WE Know AV Limited | Information & communication | 2010 |
| WE Rent Property NOW Ltd | Real estate | 2023 |
| Weavers Orchard II Management Company Limited | Households | 2009 |
| Webtwo UK Limited | Information & communication | 2007 |
| Wedoproduct Limited | Professional & scientific | 2018 |
| Wedoyoga Limited | Wholesale & retail | 2016 |
| Weee Light Ltd | Water & waste | 2008 |
| Welbeck Admin Services Limited | Professional & scientific | 2023 |
| Wellingborough Cinema Company Limited | Construction | 1922 |
| Wemovall Limited | Transport & logistics | 2025 |
| West Assets Ltd | Real estate | 2026 |
| West Groundworks Ltd | Construction | 2017 |
| West Woods Consulting Ltd | Professional & scientific | 2023 |
| Westbury Grove Management Company Limited | Households | 2012 |
| WG Medical Limited | Professional & scientific | 2024 |
| Wharf Herbert Holdings Ltd | Financial services | 2025 |
| Wheatley (Buntingford) Limited | Construction | 2014 |
| Wheatley Commercial Developments Limited | Construction | 1960 |
| Wheatley Group Developments Limited | Construction | 1961 |
| Wheatley Holdings Limited | Professional & scientific | 2014 |
| Wheatley Homes (Baldock) Ltd | Extraterritorial | 2009 |
| Wheatley Homes (PPE) Limited | Extraterritorial | 1955 |
| Wheatley Homes (Southern) Limited | Extraterritorial | 1987 |
| Wheatley Homes (WGC) Limited | Extraterritorial | 2014 |
| Wheatley Homes Limited | Construction | 1946 |
| Wheatley PLC | Real estate | 1964 |
| Wheatley Properties Limited | Real estate | 1960 |
| Wheatley Winton Hayes Limited | Construction | 1933 |
| White Lion Land (Malmesbury) Limited | Construction | 2014 |
| White Maple Software Ltd | Information & communication | 2009 |
| Whiteballoon Ltd | Other services | 2018 |
| Whiteboard Strategies Limited | Administrative & support | 2009 |
| Whiterock Capital Limited | Real estate | 2016 |
| Who's Next Properties Ltd | Real estate | 2020 |
| Wholesale Welding Supplies Limited | Wholesale & retail | 1982 |
| William & Welfare Distribution Limited | Transport & logistics | 2018 |
| Willmott Dixon Construction Limited | Construction | 1963 |
| Willmott Dixon Developments Limited | Construction | 2026 |
| Willmott Dixon FM Limited | Construction | 2009 |
| Willmott Dixon Holdings Limited | Construction | 1924 |
| Willmott Dixon Interiors Limited | Construction | 2000 |
| Willmott Dixon Limited | Construction | 2006 |
| Willow + Warren Ltd | Wholesale & retail | 2023 |
| Wimpole Holdings Limited | Extraterritorial | 2016 |
| Windermere Holdings Limited | Administrative & support | 2012 |
| Windmill Hill Management Company Limited | Households | 1978 |
| Winluxe Group Limited | Financial services | 2025 |
| Winluxe Retail Limited | Construction | 2026 |
| Winton Hayes (Midlands) Limited | Extraterritorial | 1960 |
| Winton Hayes Finance Limited | Extraterritorial | 1946 |
| Wiser Advisory Services Ltd | Professional & scientific | 2025 |
| Wisky UK Confectionery Ltd | Wholesale & retail | 2025 |
| WKH Company Services Limited | Professional & scientific | 1987 |
| Woodcote (Hitchin) Limited | Households | 1999 |
| Woodford & Warner Limited | Manufacturing | 2009 |
| Woof N WAG Dog Training CIC | Education | 2018 |
| Woolgrove Court Management (Hitchin) Limited | Households | 1970 |
| Woolgrove School Special Needs Academy | Education | 2012 |
| Wordsworth Place (Mitcham) Management Company Limited | Households | 1994 |
| Workflow Audio Visual Ltd | Wholesale & retail | 1999 |
| Worldwide Film & TV Services Ltd | Information & communication | 2019 |
| Wowssds Limited | Wholesale & retail | 2025 |
| Wraytec Limited | Professional & scientific | 2003 |
| X19 Limited | Information & communication | 2006 |
| X3RIM Creations Ltd | Manufacturing | 2025 |
| Xtra Group Limited | Financial services | 2023 |
| Xtra Homes Limited | Real estate | 2025 |
| Xtra Maintenance Ltd | Administrative & support | 2018 |
| Xtraclene Limited | Administrative & support | 2023 |
| YES Coach Ltd | Professional & scientific | 2021 |
| YJC Solutions Limited | Information & communication | 2015 |
| Yocentre Ltd | Real estate | 2022 |
| Yorkmanor Limited | Construction | 1996 |
| Youcanjustdothings Ltd | Information & communication | 2025 |
| Your Business Listing UK Limited | Administrative & support | 2017 |
| Your Family Law Ltd | Professional & scientific | 2018 |
| Youstellar Limited | Information & communication | 2023 |
| YSJ Farms (UK) Limited | Agriculture & fishing | 2026 |
| Yummy Pizza & Pasta Limited | Hospitality | 2023 |
| Z10 Safety Limited | Manufacturing | 2018 |
| ZAK Longthorpe Limited | Construction | 2022 |
| Zara Wolfenden Therapy Ltd | Health & social care | 2026 |
| Zela Recruitment Ltd | Administrative & support | 2024 |
| Zencom Ltd | Manufacturing | 2019 |
| Zerad Venture Holdings Limited | Financial services | 2025 |
| Zhimei Ltd | Wholesale & retail | 2008 |
| Ziggurat Studio Ltd | Information & communication | 2021 |
| Zinnerman Lincoln Limited | Wholesale & retail | 2014 |
| ZOE Winchester Aesthetics Ltd | Other services | 2025 |
| Zolatone Polomyx Limited | Extraterritorial | 1992 |
| Zorland Holding Ltd | Financial services | 2025 |
| Zund Property Limited | Real estate | 2023 |
| Zund UK Limited | Professional & scientific | 1993 |