| Wingbinder Limited | Manufacturing | 2019 |
| Winsburgh Limited | Real estate | 1985 |
| Winter Consultancy Services Ltd | Hospitality | 2025 |
| Winter House Investco Ltd | Real estate | 2025 |
| Winterbourne Barns Limited | Households | 2022 |
| Winterwell Racing Limited | Arts & recreation | 2016 |
| Winton & Winton Limited | Professional & scientific | 2006 |
| Wired Fish Building Services Ltd | Professional & scientific | 2020 |
| Wireless Connectivity Limited | Information & communication | 2008 |
| Wiresmith Technology Ltd | Information & communication | 2014 |
| Wise Lion Holdings Ltd | Real estate | 2020 |
| Wisenuclear Ltd | Professional & scientific | 2021 |
| Wishmoor House Ltd | Hospitality | 2006 |
| Wishmoor Property Ltd. | Real estate | 2016 |
| Woden Enterprises Ltd | Wholesale & retail | 2022 |
| Woden Events Ltd | Wholesale & retail | 2025 |
| Woden Mead Ltd | Wholesale & retail | 2025 |
| Woden Wholesale Ltd | Wholesale & retail | 2020 |
| Woodbridge Construction Consultants Limited | Construction | 2012 |
| Woodhay Energy Services Limited | Wholesale & retail | 2011 |
| Woodhay Investments | Professional & scientific | 2020 |
| Woodlands Garage (Newbury) Limited | Wholesale & retail | 2012 |
| Woodridge House Management Limited | Households | 2001 |
| Woodrow Advisory Services Limited | Other services | 2025 |
| Woodstoke Business Services Ltd | Professional & scientific | 2025 |
| Woodyett Consulting Limited | Professional & scientific | 2014 |
| Woolton Hill Argyle FC Ltd | Education | 2016 |
| Workgaps HR Ltd | Administrative & support | 2020 |
| Working Class Clothing Ltd | Manufacturing | 2019 |
| Workplace Service Solutions Ltd. | Other services | 2012 |
| Worldchief Limited | Administrative & support | 2005 |
| Worlds END Property Limited | Real estate | 2018 |
| Worthing Coaches Limited | Transport & logistics | 1977 |
| WPG Emea UK Limited | Wholesale & retail | 2022 |
| Wright Things Limited | Wholesale & retail | 2020 |
| Wrightcopy Limited | Professional & scientific | 2003 |
| Wsbourne Ltd | Construction | 2019 |
| WTE Group Holdings Limited | Professional & scientific | 2016 |
| WTG Interim Ltd | Professional & scientific | 2023 |
| Www.Realcooking.Co.Uk Ltd | Hospitality | 2006 |
| WXA Limited | Professional & scientific | 2024 |
| Wy&Sf Limited | Wholesale & retail | 2005 |
| Wyfold Property Group Ltd | Real estate | 2026 |
| Wyvern Landscapes Ltd | Administrative & support | 2024 |
| XC Comms Limited | Manufacturing | 2009 |
| Xcel Accounting Limited | Professional & scientific | 2017 |
| Xel-Lup Limited | Real estate | 2026 |
| Xeramax Limited | Professional & scientific | 2016 |
| Xiphos Strategic Safety Ltd | Professional & scientific | 2023 |
| Xitus Services UK Limited | Administrative & support | 2026 |
| XL Accounting Services Ltd | Professional & scientific | 2020 |
| Xnborne Capital Limited | Professional & scientific | 2017 |
| XP Energy Systems Limited | Manufacturing | 2001 |
| Xtel Employee Ownership Trustee Limited | Professional & scientific | 2022 |
| Xynteo Limited | Professional & scientific | 2004 |
| Yarak Limited | Professional & scientific | 2020 |
| Yattendon Group PLC | Financial services | 1934 |
| Yellow EGG Ltd | Professional & scientific | 2025 |
| Yellow River Projects Limited | Information & communication | 2012 |
| Yellowfin Media Limited | Information & communication | 2004 |
| YEW Projects Limited | Construction | 2019 |
| YEW Tree Flats Oxford Limited | Households | 2021 |
| YH Services Limited | Information & communication | 2015 |
| Yius Garden Ltd | Hospitality | 2014 |
| YM Innovation Limited | Information & communication | 2024 |
| York Road (Newbury) Management Limited | Administrative & support | 2002 |
| Yotzone Ltd | Information & communication | 2024 |
| YOU CAN DO IT Limited | Hospitality | 2013 |
| Young People and Children First | Hospitality | 2013 |
| Your "Other" Warehouse Limited | Extraterritorial | 1986 |
| Your Communications Group Limited | Professional & scientific | 2001 |
| Your Serenity Limited | Health & social care | 2018 |
| Your Wise Path Ltd | Manufacturing | 2023 |
| Ythanview Limited | Other services | 2025 |
| Zaazi Ltd | Hospitality | 2016 |
| Zainal Chong Sadli SOL Ltd | Wholesale & retail | 2026 |
| Zapata Computing U.K. Limited | Information & communication | 2021 |
| Zarkava Holdings Limited | Financial services | 2022 |
| Zarkava Limited | Professional & scientific | 2013 |
| Zckd Ltd | Information & communication | 2022 |
| Zeal Energy Ltd | Other services | 2016 |
| Zedacom Limited | Information & communication | 2012 |
| Zeebox Ltd | Wholesale & retail | 2024 |
| Zein Biotec Limited | Professional & scientific | 1998 |
| Zencro Ltd | Administrative & support | 2012 |
| Zenicofficial Ltd | Information & communication | 2020 |
| Zenit Clothing UK Limited | Wholesale & retail | 2024 |
| Zero 6 Holdings Limited | Financial services | 2018 |
| Zero 6 Projects Limited | Professional & scientific | 2006 |
| Zero 6 Property Limited | Real estate | 2018 |
| Zero Outlet Ltd | Wholesale & retail | 2026 |
| Zest Nutrition Limited | Wholesale & retail | 2022 |
| Zeus Management Consultancy Limited | Wholesale & retail | 2011 |
| Ziel Advisory Ltd | Real estate | 2020 |
| ZIN ZAN Carpets Limited | Construction | 2005 |
| Zobox Limited | Manufacturing | 2016 |
| Zoltan Ultra Haulage Ltd | Transport & logistics | 2019 |
| ZOO OST Limited | Professional & scientific | 1998 |
| Zyon Limited | Transport & logistics | 1996 |
| Zypher Tech Limited | Wholesale & retail | 2024 |