| Wisecars U.K. Limited | Other services | 2018 |
| Witts Design Limited | Manufacturing | 2014 |
| Wlic Limited | Real estate | 2025 |
| Wlpt Limited | Other services | 2015 |
| WMH Repairs Ltd | Wholesale & retail | 2021 |
| WMH Systems Engineering Ltd | Professional & scientific | 2019 |
| WMK Property Services Ltd | Transport & logistics | 2024 |
| WOK N Kebab Ltd | Hospitality | 2024 |
| Woking Foods and Wine Limited | Wholesale & retail | 2022 |
| Wolf Carpet and Flooring Ltd | Construction | 2025 |
| Wolf Transport Ltd | Transport & logistics | 2026 |
| Women for Peace in Yemen Ltd | Education | 2024 |
| Women of Glory (WOG) CIC | Health & social care | 2025 |
| Womens Football League Limited | Arts & recreation | 2022 |
| Wonder Construction Limited | Construction | 2022 |
| Wonder Goods Ltd | Wholesale & retail | 2024 |
| Wood & Stone Garden Ltd | Construction | 2014 |
| Wood END Green Management Company Limited | Households | 2013 |
| Wood Food and Wine Ltd | Wholesale & retail | 2018 |
| Woodbridge Asset Investments Ltd | Real estate | 2020 |
| Woodland Supported Accommodation Limited | Health & social care | 2002 |
| Woodley Bazaar Ltd | Wholesale & retail | 2025 |
| Woodley Empire Ltd | Real estate | 2025 |
| Wool and Black Company Ltd | Construction | 2014 |
| Worksfield Ltd | Wholesale & retail | 2026 |
| World Connecxions Ltd | Wholesale & retail | 2010 |
| World Express Freight Limited | Transport & logistics | 2002 |
| World Foods Connection Ltd | Wholesale & retail | 2025 |
| World Property Services Hayes Limited | Real estate | 2024 |
| Worldwide Fashions Ltd | Manufacturing | 2017 |
| Worton Court Ltd | Real estate | 2017 |
| Worton Court Property Management Limited | Households | 1988 |
| WOW Brows Old Town Limited | Other services | 2025 |
| WPR10 Limited | Real estate | 2019 |
| Wrapwala Ltd | Hospitality | 2026 |
| Wraysbury Tyre & Batteries Limited | Wholesale & retail | 2018 |
| Wreck Room Ltd | Arts & recreation | 2017 |
| Wrench & Flow Limited | Construction | 2025 |
| Wrra Ltd | Wholesale & retail | 2024 |
| WSB Sales Ltd | Wholesale & retail | 2023 |
| WSD Fashion Limited | Professional & scientific | 2025 |
| WSH Consultant Ltd | Professional & scientific | 2015 |
| Wsonline Ltd | Wholesale & retail | 2020 |
| WT Ventures Limited | Financial services | 2024 |
| WV1 Boutique Limited | Wholesale & retail | 2025 |
| WVO Drylining Ltd | Construction | 2026 |
| WW Wholesale Ltd | Wholesale & retail | 2016 |
| WYN Home Care Services Ltd | Health & social care | 2022 |
| Wyra Limited | Information & communication | 2016 |
| X 1 Stop Services Limited | Transport & logistics | 2026 |
| X3 Development Limited | Real estate | 2024 |
| X33 Services Limited | Transport & logistics | 2025 |
| X77 Limited | Construction | 2026 |
| Xcalibur Cricket Limited | Wholesale & retail | 2025 |
| Xclusive Care Services Ltd | Health & social care | 2023 |
| Xenon Wholesale Limited | Wholesale & retail | 2020 |
| Xero Software Ltd | Information & communication | 2021 |
| XIX Studios Ltd | Information & communication | 2025 |
| Xjas Ltd | Other services | 2019 |
| XLA Ltd | Real estate | 2026 |
| Xpert Homes Ltd | Real estate | 2019 |
| Xpress Financial Solutions Ltd | Financial services | 2026 |
| Xpress Pass Ltd | Other services | 2021 |
| Xpressions Hair and Beauty Limited | Other services | 2009 |
| Xpro Ltd | Households | 2025 |
| Xtra Mile Financial Ltd | Professional & scientific | 2012 |
| XXL Trading Limited | Wholesale & retail | 2025 |
| Xyora ARC Ltd | Wholesale & retail | 2025 |
| Y S K Builders Ltd | Construction | 2020 |
| Y. B. Transport Ltd | Transport & logistics | 2021 |
| Yaara Properties Ltd | Real estate | 2022 |
| Yaazh Vision Ltd | Health & social care | 2024 |
| Yalisa Limited | Administrative & support | 2022 |
| Yamuna House Ltd | Construction | 2016 |
| Yansu Limited | Professional & scientific | 2022 |
| YAP Transport UK Limited | Transport & logistics | 2022 |
| Yara Lara Ltd | Real estate | 2024 |
| Yaram Ltd | Health & social care | 2023 |
| Yark Properties Limited | Real estate | 2022 |
| Yash Build Limited | Construction | 2026 |
| Yash Hair & Beauty Limited | Other services | 2020 |
| Yashvi Logistics Ltd | Transport & logistics | 2025 |
| Yass Limited | Real estate | 2020 |
| Yassine Consulting Limited | Professional & scientific | 2013 |
| Yavuz Limited | Wholesale & retail | 2024 |
| Yawya Ltd | Wholesale & retail | 2026 |
| Yeading Catering Ltd | Hospitality | 2025 |
| Yeading Construction Ltd | Construction | 2025 |
| Yegna Restaurant Ltd | Administrative & support | 2017 |
| Yellow Chilli RBB Ltd | Hospitality | 2025 |
| Yellow Networks Slough Ltd | Wholesale & retail | 2020 |
| Yellow Vapes Ltd | Wholesale & retail | 2025 |
| Yghconsulting Ltd | Information & communication | 2016 |
| Yibo International Limited | Professional & scientific | 2022 |
| Yiduyidu Logistics Limited | Transport & logistics | 2026 |
| Ying NUO Consultancy Limited | Education | 2021 |
| Ykmm Limited Ltd | Wholesale & retail | 2025 |
| YMJ & Co Limited | Financial services | 2008 |
| Yogi Bears Ltd | Construction | 2021 |
| YOU Architecture Ltd | Professional & scientific | 2014 |