| William Curley Ltd | Manufacturing | 2016 |
| William O'Brien Architects Ltd | Professional & scientific | 2019 |
| Willow Comms Limited | Professional & scientific | 2018 |
| Willow Gardens Ltd | Administrative & support | 2019 |
| Willow Wines Limited | Wholesale & retail | 2012 |
| Willowdju Ltd | Professional & scientific | 2021 |
| WIN KO Ltd | Education | 2017 |
| Wingfield Farm Limited | Real estate | 2023 |
| Winify Ltd | Transport & logistics | 2020 |
| Wisdom of Brands Ltd | Professional & scientific | 2016 |
| Wise Choice Roofing Ltd | Construction | 2023 |
| Wise Food Limited | Hospitality | 2016 |
| Wise Heads Consulting Limited | Professional & scientific | 2021 |
| Wise Locations Ltd | Construction | 2026 |
| Witch Mother Ltd | Wholesale & retail | 2019 |
| Without a Paddle Brew Co Limited | Manufacturing | 2024 |
| WIZ Properties Limited | Real estate | 2003 |
| Wizard Bones Art Ltd | Arts & recreation | 2025 |
| WJC Security Ltd | Administrative & support | 2018 |
| WMC 01 Limited | Wholesale & retail | 2025 |
| WMC 02 Ltd | Wholesale & retail | 2025 |
| Women of AGE Digisales Ltd | Wholesale & retail | 2025 |
| Wonder and Wonder Limited | Extraterritorial | 2021 |
| Woodbine Close Twickenham Management Company Limited | Households | 2011 |
| Woodhead Consultancy Services Limited | Information & communication | 2011 |
| Woodlawn Medical Ltd | Health & social care | 2025 |
| Woodmead Investments Limited | Wholesale & retail | 2018 |
| Workdaytag Consulting Ltd | Information & communication | 2020 |
| Workgravity Ltd | Information & communication | 2023 |
| World for YOU Ltd | Education | 2023 |
| World Wide Publishing Limited | Information & communication | 2000 |
| Worldwide Management Solutions Ltd | Professional & scientific | 2011 |
| Woven & Woods Ltd. | Wholesale & retail | 2014 |
| WR Properties Limited | Professional & scientific | 1995 |
| Wragge Advisory Limited | Professional & scientific | 2023 |
| Wraith Barn Limited | Real estate | 2017 |
| Wright Brothers Trading Ltd | Wholesale & retail | 2023 |
| Wrightcfo Ltd | Professional & scientific | 2014 |
| WWK Consulting Group CIC | Education | 2022 |
| Xceeding Limited | Professional & scientific | 2009 |
| Xera Limited | Professional & scientific | 2012 |
| Xheka Specialists Ltd | Construction | 2024 |
| Xingu UK Limited | Administrative & support | 2015 |
| Yahmee UK Ltd | Information & communication | 2018 |
| Yandy Restaurants Limited | Hospitality | 2020 |
| Yang & Zhang Limited | Wholesale & retail | 2023 |
| YAU YAT Company Limited | Real estate | 2021 |
| YBM Consultancy Trading Ltd | Administrative & support | 2020 |
| YBY Enterprises Limited | Real estate | 2026 |
| Yellow Art Wall CIC | Arts & recreation | 2025 |
| YES Mediatech Ltd | Information & communication | 2005 |
| Yildiz Limited | Other services | 2009 |
| Ynotnow Ltd | Administrative & support | 2020 |
| Yoga Life Journeys Ltd | Health & social care | 2024 |
| Yorbik Neuroai Health and Consulting Ltd | Manufacturing | 2019 |
| York Chambers Management Ltd | Real estate | 2010 |
| Yorkshire Rugby Academy Limited | Arts & recreation | 2019 |
| Youglow Aesthetics Ltd | Other services | 2025 |
| Your Bakery Ltd | Manufacturing | 2025 |
| Your Health Digital Limited | Other services | 2023 |
| Your Music Hub Ltd | Education | 2020 |
| YP Infotech Limited | Information & communication | 2022 |
| Yr-Future Limited | Other services | 2020 |
| Yumi Design Ltd | Manufacturing | 2019 |
| Yusr Consulting Ltd | Professional & scientific | 2025 |
| Z JAN International Group Ltd | Manufacturing | 2022 |
| Z&S Business Consultants Limited | Wholesale & retail | 2016 |
| Zabala 17 Limited | Other services | 2016 |
| Zacuska Limited | Wholesale & retail | 2024 |
| ZAF Shoes Limited | Wholesale & retail | 2023 |
| Zafeon Limited | Professional & scientific | 2013 |
| Zante Catering Ltd | Hospitality | 2025 |
| Zara Carpet Ltd | Transport & logistics | 2016 |
| Zaytoon Holding Limited | Real estate | 2019 |
| Zebio Ltd | Information & communication | 2012 |
| Zeitgeist Books Ltd | Wholesale & retail | 2022 |
| Zella Books Limited | Information & communication | 2014 |
| ZEN Space Retreats Ltd | Hospitality | 2022 |
| Zenith Altus Ltd | Information & communication | 2025 |
| Zenith Solutions Ltd | Construction | 2025 |
| Zero to TEN Limited | Information & communication | 2014 |
| Zestygreen Ltd | Real estate | 2012 |
| Zeta Global Trading Ltd | Wholesale & retail | 2024 |
| Zeza Limited | Wholesale & retail | 2025 |
| ZF Legal Services Limited | Professional & scientific | 2026 |
| ZH Tech Ltd | Wholesale & retail | 2025 |
| ZIA Maria Ltd | Hospitality | 2026 |
| Zilkroses Care Limited | Health & social care | 2014 |
| Zimmermann Limited | Information & communication | 2015 |
| Zinaya Enterprises Ltd | Real estate | 2025 |
| ZL Domus Limited | Real estate | 2015 |
| ZMJ Enterprises Ltd | Real estate | 2022 |
| ZOE L'Oud Limited | Real estate | 2020 |
| Zoefit UK Ltd | Arts & recreation | 2023 |
| Zombie Limited | Professional & scientific | 2022 |
| Zoomingu Ltd | Information & communication | 2013 |
| Zrzutka UK Ltd | Information & communication | 2020 |
| ZS Pharm Services Ltd | Wholesale & retail | 2023 |
| ZZZ Limited | Administrative & support | 2002 |
| ZZZ Scape Ltd | Real estate | 2021 |