| Winchester Property Management Ltd | Real estate | 2017 |
| Winchester Tree Surgeons Limited | Agriculture & fishing | 1997 |
| Winchford Ltd | Real estate | 2018 |
| Wind Services Ltd | Administrative & support | 2022 |
| Wings Like Eagles | Transport & logistics | 2007 |
| Winright Investments Limited | Real estate | 2017 |
| Winright Limited | Extraterritorial | 2017 |
| Winright Properties Limited | Extraterritorial | 2017 |
| Winters Place Management Company Limited | Administrative & support | 2010 |
| Winton Design Ltd | Wholesale & retail | 2023 |
| Winton Place (Maidenhead) Management Limited | Households | 2013 |
| Wired Services Limited | Manufacturing | 2025 |
| Wise World Studio Ltd | Professional & scientific | 2026 |
| Wiser Recycling Limited | Water & waste | 2003 |
| Wisp Cortex Ltd | Information & communication | 2025 |
| WLE Logistics Limited | Transport & logistics | 2008 |
| WMA Investments Ltd | Wholesale & retail | 2023 |
| Wmil Group Limited | Financial services | 2023 |
| WMT Removals Ltd | Transport & logistics | 2025 |
| Wolf Security (N.W.) Limited | Administrative & support | 2006 |
| Wolfson Electrostatics Limited | Administrative & support | 2006 |
| Women in Football | Other services | 2012 |
| Wonder Gate Marketing Ltd | Professional & scientific | 2021 |
| WOO Cars Ltd | Wholesale & retail | 2021 |
| WOO Ltd | Wholesale & retail | 2021 |
| Woodcubed Limited | Manufacturing | 2023 |
| Woodgrange (2010) Limited | Real estate | 2010 |
| Woodgrange (Wembley) Estates Limited | Real estate | 1963 |
| Woodhouse Upholstery Limited | Other services | 2012 |
| Woodhurst Capital Management Ltd | Real estate | 2018 |
| Woodhurst Park Management Limited | Households | 2015 |
| Woodlands Outdoor Leisure Ltd. | Arts & recreation | 2012 |
| Woodside Avenue Homes LLP | | 2018 |
| Woodside Properties Southern Ltd | Real estate | 2019 |
| Woodside Trading Estate Management Company Limited | Households | 2007 |
| Woodwork Properties Ltd | Real estate | 2024 |
| Wookanana Limited | Information & communication | 2016 |
| Woosabi Street Kitchen Ltd | Hospitality | 2025 |
| Worgret Road Management Limited | Households | 2014 |
| Work Here Work There Ltd | Information & communication | 2017 |
| Workdry (Pump Hire & Sales) Limited | Construction | 1976 |
| Workdry International Bidco Limited | Financial services | 2022 |
| Workdry International Debtco Limited | Financial services | 2025 |
| Workdry International Holdco Limited | Financial services | 2022 |
| Workdry International Limited | Construction | 2014 |
| Workdry International Midco Limited | Financial services | 2022 |
| Workdry International Topco Limited | Financial services | 2022 |
| Worktown Limited | Administrative & support | 1978 |
| Worktown Office Supplies Limited | Wholesale & retail | 1984 |
| Worktown Properties Limited | Real estate | 1980 |
| Workuat Ltd | Administrative & support | 2015 |
| Workzone Ltd | Administrative & support | 2020 |
| World of Motion Limited | Wholesale & retail | 2007 |
| World Rescue Organisation | Education | 2002 |
| Worldfast Ltd | Financial services | 2008 |
| Worldwide Diamond Exchange (UK) Limited | Professional & scientific | 2020 |
| Worldwide News Limited | Information & communication | 2020 |
| WRO Sales Limited | Wholesale & retail | 2022 |
| Wtgil Limited | Professional & scientific | 2010 |
| Wtgisl Limited | Financial services | 2010 |
| Wykeham Homes Ltd | Construction | 2015 |
| Wyvern College Academy Trust | Education | 2012 |
| Wyvern Community Enterprise Limited | Arts & recreation | 2012 |
| XB44 Ltd | Professional & scientific | 2023 |
| Xela Group Ltd | Transport & logistics | 2021 |
| Xelabus Limited | Transport & logistics | 2010 |
| Xeriontech Ltd | Information & communication | 2015 |
| Xonetic Limited | Information & communication | 1994 |
| Xpec Consulting Limited | Education | 2017 |
| XYZ Barber's Ltd | Other services | 2026 |
| Xzibit Ltd | Wholesale & retail | 2011 |
| Y2K Club Limited | Wholesale & retail | 2025 |
| YAN Construction Engineering Limited | Construction | 2017 |
| Yan&Mark Property Ltd | Real estate | 2024 |
| Yang Ping Limited | Health & social care | 2021 |
| Yardley Wood Limited | Real estate | 2025 |
| Yarlington Homes Limited | Construction | 2003 |
| Yarlington Treasury Services PLC | Financial services | 2017 |
| Yarnton Nurseries LLP | | 2008 |
| Yash Housing Ltd | Real estate | 2025 |
| Yegane Limited | Real estate | 2019 |
| Yeganeh Group Limited | Hospitality | 2026 |
| Yellow Box Studio Ltd | Professional & scientific | 2024 |
| Yellowfin Capital Limited | Financial services | 2017 |
| Yellowkayne Aviation Limited | Transport & logistics | 2016 |
| Yener Group Ltd | Hospitality | 2024 |
| YES WE Sell Ltd | Wholesale & retail | 2024 |
| YEW Tree Farm (Launton) Management Limited | Households | 2014 |
| Yewtree Estate Management Limited | Real estate | 2024 |
| Yieldbourne Limited | Construction | 1984 |
| YKM Media Limited | Professional & scientific | 2024 |
| Yogi Bapa Limited | Wholesale & retail | 2021 |
| Yonge Cottage Ltd | Financial services | 2026 |
| Yoobox Ltd | Wholesale & retail | 2012 |
| Yorulmaz Enterprises Limited | Hospitality | 2022 |
| Yorulmaz Investments Limited | Real estate | 2012 |
| YOU ASK WE Supply Ltd. | Information & communication | 2014 |
| You'Re the Boss Enterprises Limited | Professional & scientific | 2011 |
| Youmans and Sons Limited | Construction | 2016 |
| Youmatteruk Ltd | Health & social care | 2010 |