| Willsea Data Solutions Ltd | Information & communication | 2015 |
| Willy & Noah Investments Ltd | Real estate | 2024 |
| Wilson HAY Projects Limited | Administrative & support | 2008 |
| Wilson Health Ltd | Information & communication | 2014 |
| Wimblehomes Ltd | Real estate | 2024 |
| Windmill AVE Media Ltd | Manufacturing | 2019 |
| Window Doctors Installations Ltd | Construction | 2025 |
| Winevalley Ltd | Wholesale & retail | 2022 |
| Winning and Sons Limited | Construction | 2014 |
| Winston South Ltd | Wholesale & retail | 2014 |
| Winston Web Co Ltd | Professional & scientific | 2023 |
| Wisdom Made Easy Ltd | Professional & scientific | 2023 |
| Wise Property and Consultancy Services Limited | Professional & scientific | 2020 |
| Witney Pharma Ltd | Wholesale & retail | 2026 |
| WJJ Properties Limited | Real estate | 2018 |
| WMP Management Ltd | Households | 2023 |
| WOK One Limited | Hospitality | 2011 |
| Wolvercote Young People's Club Limited | Arts & recreation | 2012 |
| Wonderwall Events UK Ltd | Professional & scientific | 2025 |
| Wong and KAM Limited | Real estate | 2003 |
| Wong Property Management Ltd | Real estate | 2015 |
| Wood END Property Management Ltd | Real estate | 2023 |
| Woodedd Property Ltd | Real estate | 2022 |
| Woodstock Wardrobe Company Limited | Manufacturing | 2026 |
| Woodwards Interiors Limited | Construction | 2011 |
| Workability Support Ltd | Professional & scientific | 2021 |
| World of Walls Ltd | Real estate | 2023 |
| World Place Ltd | Transport & logistics | 2023 |
| Worldwide Automotive Limited | Wholesale & retail | 2002 |
| Worthington Associates Limited | Households | 1989 |
| Wrapitta Ltd | Hospitality | 2023 |
| Wrapitta-Uk Limited | Hospitality | 2025 |
| Wright Dental Ltd | Health & social care | 2024 |
| Wringford Cottages Limited | Hospitality | 2021 |
| Writing Clarity Limited | Arts & recreation | 2019 |
| Wwes Limited | Construction | 2005 |
| Wychwood Carpentry & Joinery Ltd | Construction | 2026 |
| Wykham Park Retail Ltd | Wholesale & retail | 2018 |
| Wynns Plumbing and Heating Ltd | Construction | 2026 |
| Wytham House Management Company Limited | Hospitality | 2015 |
| X26 Ltd | Information & communication | 2019 |
| Xentech Solutions Limited | Information & communication | 2007 |
| Xgen RF Limited | Other services | 2020 |
| XL Direct Limited | Information & communication | 2003 |
| XLF Solutions Ltd | Professional & scientific | 2025 |
| XOR Limited | Information & communication | 2022 |
| XPLUS2 Property Group Ltd | Financial services | 2023 |
| Xpression Event Solutions Limited | Transport & logistics | 2007 |
| XS Beauty Limited | Health & social care | 2019 |
| Xtalos Ltd | Professional & scientific | 2024 |
| Y5MEO LLP | | 2023 |
| Yacht Hard 8 LLP | | 2017 |
| Yanga Services Ltd. | Professional & scientific | 2020 |
| Yates Caravans Ltd | Transport & logistics | 2018 |
| YDP Oxfordshire Ltd | Education | 2021 |
| Yellow Spider Ltd | Professional & scientific | 2014 |
| Yellowbird Homes Ltd | Health & social care | 2024 |
| Yena International Limited | Wholesale & retail | 2016 |
| Yenikent Limited | Real estate | 2019 |
| Yeulet & Co Ltd | Construction | 2024 |
| Yixuan Building Ltd | Construction | 2021 |
| YOO Fashion Limited | Wholesale & retail | 2017 |
| Yorkshire Exotics Ltd | Manufacturing | 2026 |
| Young’S Roofing Services Limited | Construction | 2020 |
| Your Vision Wealth Management Limited | Financial services | 2022 |
| Yuen Sing TAI Ltd | Administrative & support | 2017 |
| Yugabyte UK Limited | Information & communication | 2020 |
| Yvie Ltd | Information & communication | 2024 |
| YWS Properties Limited | Real estate | 2023 |
| Z&A Apparel Limited | Wholesale & retail | 2026 |
| Zachary Coles DRY Stone Walling Ltd | Manufacturing | 2025 |
| Zahra Wholesale and Logistics Co. Ltd | Wholesale & retail | 2025 |
| Zedworks Ltd | Professional & scientific | 2026 |
| Zenith Clinical Consultancy Ltd | Professional & scientific | 2009 |
| Zenith Smile Limited | Health & social care | 2025 |
| Zenlyt Ltd | Information & communication | 2026 |
| Zenride Ltd | Wholesale & retail | 2025 |
| Zephyr Global Limited | Professional & scientific | 2023 |
| Zima Homes Ltd | Real estate | 2025 |
| Zima Limited | Information & communication | 1996 |
| Zimplants Ltd | Administrative & support | 2016 |
| Zonemerge Limited | Real estate | 1997 |
| Zotari Limited | Professional & scientific | 2016 |
| ZTC Interiors Limited | Professional & scientific | 2023 |
| Zuki's Hair and Beauty Ltd | Other services | 2026 |