| Yard Board Ltd | Administrative & support | 2026 |
| Yardstone Consultants Ltd | Information & communication | 2012 |
| Yarn Legacy Ltd | Professional & scientific | 2025 |
| Yaso Ltd | Wholesale & retail | 2025 |
| Ychaos Limited | Professional & scientific | 2022 |
| YD Decorating Services Ltd | Construction | 2024 |
| Yearbook Ltd | Other services | 2020 |
| YEG Food Hall Ltd | Manufacturing | 2026 |
| YEG Logistic Ltd | Transport & logistics | 2023 |
| YEG Vehicle Solutions Ltd | Wholesale & retail | 2023 |
| Yellow HAT Solutions Ltd | Professional & scientific | 2008 |
| Yellow Jersey Consulting Limited | Information & communication | 2008 |
| Yellow Lifestyle and Luxury Limited | Arts & recreation | 2024 |
| YEW Tree Bottom Road Limited | Construction | 2022 |
| YEW Tree Close (Epsom) Management Company Limited | Households | 2011 |
| Yildiz Global Ltd | Wholesale & retail | 2025 |
| Yilord Ltd | Construction | 2020 |
| YJW Ltd | Wholesale & retail | 2023 |
| YMG Kitchens Limited | Hospitality | 2025 |
| Ynco Ltd | Health & social care | 2025 |
| YNR Limited | Transport & logistics | 2019 |
| YO Sarnie Limited | Wholesale & retail | 2017 |
| Yokh Limited | Hospitality | 2013 |
| YOO Accountancy Ltd | Professional & scientific | 2010 |
| Yorcastle Limited | Real estate | 2017 |
| York Defence Group Ltd | Administrative & support | 2024 |
| York House (Lower Kingswood) Management Company Limited | Households | 2002 |
| Yotors Limited | Information & communication | 2012 |
| Yotors.Com Limited | Extraterritorial | 2011 |
| Youcanlogin Ltd | Information & communication | 2010 |
| Youff CIC | Education | 2025 |
| Youmeandthesaltysea Ltd | Information & communication | 2020 |
| Youngs Waste Clearance Ltd | Water & waste | 2020 |
| Your HR Support Ltd | Administrative & support | 2021 |
| Your Quality Care Group Limited | Health & social care | 2017 |
| Your Quality Care Services Ltd | Health & social care | 2010 |
| Your Taxi Transfer Limited | Transport & logistics | 2024 |
| Yours Local Limited | Wholesale & retail | 2022 |
| Youth Access | Health & social care | 1994 |
| Yuchin Limited | Other services | 2001 |
| Yumez Ltd | Wholesale & retail | 2024 |
| Yummy Foods PVT Limited | Hospitality | 2020 |
| Yuppies Limited | Households | 1986 |
| Yusuf House Ltd | Real estate | 2023 |
| Yuza Holdings Limited | Financial services | 2012 |
| Yuza Media Limited | Information & communication | 2010 |
| Yvan Fabing Ltd | Professional & scientific | 2014 |
| YYG Buldrop Ltd | Transport & logistics | 2015 |
| YYG Global Ltd | Transport & logistics | 2013 |
| Zacandaslam Ltd | Information & communication | 2022 |
| Zaddix Ltd | Professional & scientific | 2025 |
| Zafar and Sons Limited | Other services | 2024 |
| Zagreus Developments Limited | Construction | 2025 |
| Zakuani Quality Care Ltd | Health & social care | 2026 |
| Zakz Ltd | Wholesale & retail | 2019 |
| Zampa Media Limited | Information & communication | 2025 |
| Zara Mills Limited | Arts & recreation | 2019 |
| Zaya Kitchens Limited | Wholesale & retail | 2017 |
| Zebraz Ltd | Wholesale & retail | 2022 |
| ZED Online Ltd | Extraterritorial | 2017 |
| ZED Power Ltd | Construction | 2018 |
| Zemits UK Ltd | Wholesale & retail | 2020 |
| ZEN 'N' Fit Limited | Arts & recreation | 2002 |
| Zenith Entertainment International Ltd | Information & communication | 2015 |
| Zenzi Hospitality Limited | Wholesale & retail | 2019 |
| Zeplake Limited | Wholesale & retail | 2010 |
| Zestan Trading Ltd | Wholesale & retail | 2015 |
| ZH Solutions Limited | Manufacturing | 2021 |
| Zhenman Investments Limited | Real estate | 2024 |
| ZIG ZAG Creperie Ltd | Hospitality | 2023 |
| Zildjian (UK) Limited | Wholesale & retail | 1989 |
| ZIT - Car & Home Memorable Care Ltd | Wholesale & retail | 2020 |
| Ziyou Ventures Limited | Financial services | 2024 |
| ZN Barbers Epsom Ltd | Other services | 2026 |
| Zodian Media Limited | Information & communication | 2020 |
| Zombie Neighbours Ltd | Other services | 2007 |
| Zoneacre Limited | Households | 1986 |
| Zorba Consulting Limited | Administrative & support | 2006 |
| Zorin Enterprises Limited | Wholesale & retail | 2002 |
| ZPM Consultancy Ltd | Real estate | 2023 |
| ZPM Properties Ltd | Real estate | 2019 |
| Zprung Limited | Information & communication | 2023 |
| ZS Medical Ltd | Professional & scientific | 2020 |
| Ztply UK Ltd | Wholesale & retail | 2016 |
| Zulu Foxtrot Golf Ltd | Construction | 2023 |
| Zuma London Ltd | Construction | 2018 |