| Waterhall Farm Equestrian Limited | Other services | 2020 |
| Wathnan Racing (UK) Limited | Arts & recreation | 2024 |
| Wattlefield Hall Stud Limited | Real estate | 1994 |
| Wawwi Limited | Professional & scientific | 2016 |
| Wayne Thompson Limited | Construction | 2014 |
| Wellbeing Warehouse Ltd | Arts & recreation | 2013 |
| Wenhaston Holdings Limited | Financial services | 2020 |
| WER Global Ltd | Professional & scientific | 2019 |
| West's Garage (Bedford) Limited | Real estate | 2013 |
| West's Garage (H) (Bedford) Limited | Financial services | 2013 |
| West's Garage (H) (KL) Limited | Financial services | 2013 |
| West's Garage (H) (Newmarket) Limited | Financial services | 2013 |
| West's Garage (KL) Limited | Real estate | 2013 |
| West's Garage (Newmarket) Limited | Wholesale & retail | 1985 |
| WGBLUE3 Ltd | Health & social care | 2024 |
| What Rights Limited | Professional & scientific | 2012 |
| What the Fleur Ltd | Wholesale & retail | 2022 |
| Whbrowns Ltd | Wholesale & retail | 2026 |
| Wheelers Eplatform Limited | | 2021 |
| Where ARE YOU Going Today Ltd | Information & communication | 2024 |
| White Lion Sawston Ltd | Hospitality | 2019 |
| White Oak Properties Limited | Construction | 2008 |
| White Tara UK Limited | Other services | 2017 |
| Whiteley and Creasy (Cambridge) Limited | Wholesale & retail | 1947 |
| Whiteley Properties Limited | Real estate | 2001 |
| Whitlock Psychology Ltd | Health & social care | 2025 |
| Whorl Publishing Limited | Information & communication | 2009 |
| Whyt Tile Co Limited | Wholesale & retail | 2018 |
| Wickhambrook Medical Services Ltd | Health & social care | 2008 |
| Wickhambrook Stores Limited | Wholesale & retail | 2016 |
| Wild Tracks Limited | Arts & recreation | 1992 |
| Will Edmeades Bloodstock Ltd | Professional & scientific | 2003 |
| William Knight Racing Limited | Arts & recreation | 2005 |
| Williams Heating Ltd | Construction | 2016 |
| Willingham House Stud Ltd | Agriculture & fishing | 2003 |
| Willis Property Holdings Ltd | Transport & logistics | 2024 |
| Willow Hair Consultants Limited | Other services | 2011 |
| Willow Payroll Services Limited | Professional & scientific | 2021 |
| Wilson Consultancy Services Ltd | Administrative & support | 2017 |
| Wilson Physio Ltd | Health & social care | 2013 |
| Windrose Limited | Professional & scientific | 2020 |
| Winson-Pearce Limited | Professional & scientific | 2021 |
| Wisby Entertainment Ltd | Wholesale & retail | 2020 |
| WJ Ltd | Extraterritorial | 2007 |
| Woefac Holdings Limited | Financial services | 2017 |
| Wonde Limited | Information & communication | 2022 |
| WOODBARN2022 Limited | Real estate | 2022 |
| Woodmans Consulting Limited | Information & communication | 2010 |
| Woodward Drive Ltd | Real estate | 2011 |
| Workplace Futures Limited | Professional & scientific | 2006 |
| Worthstrike Limited | Extraterritorial | 1976 |
| Woven Tech Ltd | Information & communication | 2024 |
| WP Limited | Extraterritorial | 2007 |
| Wright & Sons Painting Contractors UK Ltd | Construction | 2025 |
| Wrume Ltd | Wholesale & retail | 2022 |
| Wyck Livestock Limited | Agriculture & fishing | 1982 |
| Wyte Limited | Wholesale & retail | 2026 |
| Xcell Dogs Limited | Agriculture & fishing | 2020 |
| Xention Pharma Limited | Administrative & support | 2010 |
| Xeopoint.Com Limited | Information & communication | 2011 |
| XI Ltd | Extraterritorial | 2010 |
| XK Ltd | Extraterritorial | 2009 |
| XM Capital Limited | Real estate | 2020 |
| Xpectra Ltd | Manufacturing | 2020 |
| XR Ltd | Extraterritorial | 2009 |
| Xtax Accountancy Services Limited | Professional & scientific | 2013 |
| Xtreme Sales Ltd | Other services | 2026 |
| Xxix Campbell Ltd | Transport & logistics | 2016 |
| YA Ltd | Extraterritorial | 2008 |
| YB Ltd | Extraterritorial | 2008 |
| YC Ltd | Extraterritorial | 2022 |
| YE Ltd | Extraterritorial | 2009 |
| Yeter & Son's Ltd | Real estate | 2023 |
| YEW Tree Homes (Suffolk) Ltd | Construction | 2020 |
| YI Ltd | Extraterritorial | 2020 |
| Yiayia Cookies Limited | Manufacturing | 2024 |
| Yopey | Professional & scientific | 2011 |
| Yorkshire Equine Clinic Limited | Professional & scientific | 2013 |
| Yorkshire Equine Hospital Limited | Professional & scientific | 2013 |
| Yorkshire Hideaways Limited | Extraterritorial | 2020 |
| Young People of the Year Limited | Professional & scientific | 1997 |
| Youngblood Properties Ltd | Real estate | 2021 |
| Your Changing Life Ltd | Health & social care | 2020 |
| Your Next Chapter Today Ltd | Professional & scientific | 2015 |
| YR Ltd | Extraterritorial | 2020 |
| YU Limited | Extraterritorial | 2007 |
| Yutree Group Ltd | Professional & scientific | 2011 |
| Yutree Insurance Ltd | Financial services | 2011 |
| Yutree Ltd | Extraterritorial | 2011 |
| Yutree Topco Limited | Professional & scientific | 2025 |
| YV Limited | Extraterritorial | 2008 |
| YY Ltd | Extraterritorial | 2009 |
| Z Ltd | Extraterritorial | 2008 |
| Zafira Limited | Real estate | 2002 |
| Zaymar Consultancy Services Limited | Professional & scientific | 2008 |
| Zephora Modelling Limited | Professional & scientific | 2024 |
| Zero Action CIC | Information & communication | 2014 |
| ZG Ltd | Extraterritorial | 2009 |
| ZH Limited | Extraterritorial | 2008 |
| ZK Property Solutions Limited | Real estate | 2026 |