| Wright Wills Estate Planning Limited | Professional & scientific | 2018 |
| Write on Media Limited | Administrative & support | 2012 |
| Writtle Construction Group Ltd | Construction | 2023 |
| WV Dentistry Limited | Health & social care | 2017 |
| WZN Builders and Developers Limited | Construction | 2025 |
| Xallante Limited | Professional & scientific | 2014 |
| Xanland Limited | Other services | 2026 |
| Xanwood Limited | Other services | 2020 |
| Xero Construction Group Limited | Construction | 2024 |
| Xich LO Hornchurch Ltd | Hospitality | 2018 |
| XL Drive Ltd | Education | 2023 |
| Xorb Limited | Real estate | 2010 |
| XT Group Limited | Administrative & support | 2024 |
| Xtix Ltd | Information & communication | 2017 |
| Yanimise Estates Ltd | Construction | 2022 |
| Yarnton Landlord Limited | Real estate | 2021 |
| YAU Clan Association UK Ltd | Other services | 2015 |
| Yellowtail Publishing Limited | Information & communication | 2013 |
| Yeoman Interpreting Services Ltd | Professional & scientific | 2011 |
| YES YOU CAN International Consultant Ltd | Education | 2025 |
| YES4SECURITY Ltd | Administrative & support | 2024 |
| Yfood Ltd | Hospitality | 2016 |
| Yieldsteel Limited | Wholesale & retail | 2011 |
| Yippidoo Events Ltd | Arts & recreation | 2017 |
| Yoden Properties Limited | Real estate | 2025 |
| YOU and ME Counselling | Health & social care | 2012 |
| Young Culture Ltd | Information & communication | 2018 |
| Young Explorers Pre-School Limited | Education | 2012 |
| Young Explorers Pre-School of Weybridge Ltd | Education | 2019 |
| Youngagain Cycles Limited | Manufacturing | 2017 |
| Youngbeautyx Ltd | Other services | 2024 |
| Youngs Travel Ltd | Administrative & support | 2013 |
| Your Financial Footprint Limited | Professional & scientific | 2010 |
| Your Home Property Management Services Ltd | Administrative & support | 2024 |
| Your Sweet Party Limited | Education | 2022 |
| YS Online Central Ltd | Wholesale & retail | 2022 |
| Yume Imagination Ltd | Manufacturing | 2025 |
| Yume Property Ltd | Real estate | 2025 |
| Zack Caunt Ltd | Health & social care | 2025 |
| Zahid Technology Solutions Limited | Information & communication | 2022 |
| Zaidisons Limited | Professional & scientific | 2014 |
| Zailum Ltd | Information & communication | 2024 |
| Zama Shop Ltd | Wholesale & retail | 2025 |
| Zana London Limited | Hospitality | 2024 |
| Zanata Traiding Ltd | Wholesale & retail | 2019 |
| Zane Venues Limited | Real estate | 2025 |
| ZAR Sepideh Ltd | Health & social care | 2026 |
| Zara & Co Homes Ltd | Real estate | 2017 |
| Zara-Naya Ltd | Health & social care | 2022 |
| Zare Estates Ltd | Real estate | 2025 |
| Zark Ventures Limited | Administrative & support | 2019 |
| ZBA Services Limited | Professional & scientific | 2011 |
| Ze-Tech Services Ltd | Wholesale & retail | 2024 |
| Zedtek Limited | Information & communication | 2007 |
| Zeebro UK Ltd | Wholesale & retail | 2025 |
| Zeeshan Digital Limited | Wholesale & retail | 2025 |
| Zeitouna Limited | Real estate | 2019 |
| ZEN Droid Limited | Information & communication | 2012 |
| ZEN Lights Studio Ltd | Professional & scientific | 2025 |
| ZEN Therapy London Ltd | Other services | 2016 |
| Zeneli Plumbers Limited | Construction | 2019 |
| Zenith Rubber UK Limited | Manufacturing | 2013 |
| Zenzen Global Limited | Construction | 2025 |
| Zephyr Recruit Ltd | Administrative & support | 2023 |
| Zeppelin Roofing Ltd | Construction | 2021 |
| Zerlanis Limited | Real estate | 2021 |
| Zero DRY Time (Billericay) Limited | Other services | 2024 |
| ZERO7 Restaurant and Bar Ltd | Hospitality | 2023 |
| Zess Limited | Wholesale & retail | 2021 |
| ZF Picks Ltd | Wholesale & retail | 2025 |
| Ziggy Contracts Ltd | Construction | 2021 |
| Zikrly Ltd | Wholesale & retail | 2024 |
| Zinara Ltd | Health & social care | 2024 |
| Zingzone Limited | Wholesale & retail | 2006 |
| Zinner Investments Limited | Real estate | 2024 |
| Zion Gold Ltd | Real estate | 2020 |
| Zizu Construction Ltd | Construction | 2020 |
| Zmib Limited | Health & social care | 2023 |
| ZMZ Property One Limited | Real estate | 2023 |
| ZRB Consulting Ltd | Financial services | 2021 |
| ZRD Engineering Ltd | Professional & scientific | 2018 |
| ZRF Electrical Limited | Construction | 2024 |
| Zuddha Water Limited | Manufacturing | 2017 |
| Zupet Ltd | Information & communication | 2025 |
| Zutan Limited | Hospitality | 2018 |
| ZX6 Limited | Wholesale & retail | 2020 |
| Zyberi & Sons Capital Investments Limited | Real estate | 2019 |
| Zyberi Builders and Developers Ltd | Construction | 2025 |
| Zyric Group Ltd | Hospitality | 2025 |