| Ybdm Ltd | Wholesale & retail | 2025 |
| Yell Estates Ltd | Real estate | 2013 |
| Yellowrose Limited | Professional & scientific | 2020 |
| Yellowtriangle Ltd | Real estate | 2023 |
| Yeraki Array Ltd | Wholesale & retail | 2026 |
| YET Holding Limited | Financial services | 2018 |
| YGT Group Ltd | Wholesale & retail | 2025 |
| YGT Ltd | Wholesale & retail | 2024 |
| YK Consulting Limited | Information & communication | 2015 |
| Ylcn Ltd | Wholesale & retail | 2025 |
| YMA Properties Ltd | Real estate | 2023 |
| Ymor Commercial Limited | Financial services | 2024 |
| Ymor Limited | Financial services | 2019 |
| Ynna Style Ltd | Other services | 2020 |
| Yoga Training Centre Ltd | Education | 2014 |
| Yogi Travel World Ltd | Administrative & support | 2026 |
| Yogoloji Limited | Health & social care | 2003 |
| Yoko Sizzlers Ltd | Hospitality | 2019 |
| Yorkvale Limited | Wholesale & retail | 2012 |
| YOU Passed Ltd | Education | 2024 |
| Youconnectz Ltd | Information & communication | 2010 |
| Youmakr Ltd | Information & communication | 2017 |
| Young Believers Limited | Information & communication | 2019 |
| Young Consultancy Ltd | Professional & scientific | 2020 |
| Young Knights Express UK Ltd | Wholesale & retail | 2017 |
| Your City Office Limited | Administrative & support | 2006 |
| Your Tax Help Ltd | Professional & scientific | 2019 |
| Youtrigger Limited | Professional & scientific | 2011 |
| YS Design Studio Ltd | Professional & scientific | 2019 |
| Ysbconsult Ltd | Real estate | 2026 |
| Yummy Limited | Hospitality | 1998 |
| Yunicorn Limited | Real estate | 2000 |
| Yusor Health Ltd | Health & social care | 2025 |
| Z & T Hair Treatments Ltd | Health & social care | 2021 |
| Z & Z Global Holdings Ltd | Professional & scientific | 2025 |
| Z Finance Commodity Trading Limited | Wholesale & retail | 2025 |
| Z&S Builders Ltd | Construction | 2020 |
| ZA Viedeza Technologies Limited | Manufacturing | 2023 |
| Zaag Stanmore Ltd | Real estate | 2025 |
| Zack Gabriel Ltd | Wholesale & retail | 2022 |
| Zaeton UK Limited | Wholesale & retail | 2017 |
| ZAI & Co 7 Ltd | Hospitality | 2021 |
| Zaiden Limited | Wholesale & retail | 2017 |
| Zalah Limited | Transport & logistics | 2026 |
| Zaman Clothing Ltd | Wholesale & retail | 2019 |
| Zamzam International Ltd | Administrative & support | 2024 |
| Zanec Technologies (Europe) Limited | Information & communication | 2008 |
| Zapp It&C Limited | Other services | 2018 |
| Zarling Health Solutions Ltd | Health & social care | 2023 |
| Zarna Asset Management Ltd | Real estate | 2025 |
| Zarna Limited | Wholesale & retail | 2016 |
| ZAS Property Holdings Limited | Real estate | 2025 |
| Zavian Holdings Ltd | Real estate | 2020 |
| Zayan SM Ltd | Education | 2024 |
| Zazou Emporium Limited | Information & communication | 2011 |
| Zazou Properties Limited | Real estate | 2024 |
| Zcqt Ltd | Financial services | 2025 |
| ZDH Property Ltd | Real estate | 2023 |
| Zebra Trading Corporation Ltd | Wholesale & retail | 2006 |
| Zeca-Dent Limited | Health & social care | 2021 |
| ZEE Entertainment UK Limited | Information & communication | 2023 |
| Zeekook Ltd | Manufacturing | 2020 |
| Zeel Enterprise Ltd | Construction | 2023 |
| Zeenety Jewellery Ltd | Wholesale & retail | 2025 |
| ZEN Squared Limited | Information & communication | 2013 |
| Zendoo Limited | Professional & scientific | 2025 |
| Zenmode Ltd | Information & communication | 2025 |
| Zenn Consultancy Limited | Professional & scientific | 2021 |
| Zenyatta House Limited | Households | 2024 |
| ZES Property Services Limited | Real estate | 2020 |
| Zest Investments Ltd | Real estate | 2019 |
| Zeto Consultancy Services Limited | Wholesale & retail | 2012 |
| ZHU Property Group Limited | Real estate | 2025 |
| Zian Hi-Tech (U.K.) Limited | Wholesale & retail | 1998 |
| Zian Services Ltd | Construction | 2022 |
| ZMR Enterprise Limited | Other services | 2012 |
| Zojs Limited | Real estate | 2018 |
| ZOO Music Limited | Information & communication | 1978 |
| Zookx Limited | Administrative & support | 2003 |
| Zophia Homes Ltd | Real estate | 2023 |
| ZSR Investments Ltd | Real estate | 2024 |
| ZTJ Travel Ltd | Administrative & support | 2024 |
| Zuma Days Limited | Arts & recreation | 2006 |
| Zuma Holdings Ltd | Real estate | 2026 |
| Zumar Perfumes Ltd | Wholesale & retail | 2024 |
| Zuri Assets (Stanmore) Ltd | Real estate | 2026 |
| Zuri Assets Ltd | Real estate | 2025 |
| Zuri Consultancy Ltd | Professional & scientific | 2025 |
| Zuri Limited | Wholesale & retail | 2006 |
| Zygo Health Ltd | Wholesale & retail | 2025 |
| Zylog Systems (Europe) Limited | Information & communication | 2004 |
| Zynp Ltd | Wholesale & retail | 2025 |
| Zyragems Ltd | Wholesale & retail | 2025 |
| ZZS Trading Company Limited | Administrative & support | 2009 |