| Workwise Cleaning Limited | Health & social care | 2023 |
| Worldbooth Limited | Wholesale & retail | 2021 |
| WOW Hand Car Wash Ltd | Wholesale & retail | 2020 |
| Wrighttax Ltd | Professional & scientific | 2025 |
| Wynnyou Limited | Wholesale & retail | 2021 |
| XG Solutions Ltd | Construction | 2018 |
| Xivfx Limited | Professional & scientific | 2016 |
| XPE Mobile Ltd | Information & communication | 2011 |
| XYZ Property Ltd | Real estate | 2015 |
| Y-Square Solutions Limited | Information & communication | 2008 |
| Yardley Carpentry and Flooring Ltd | Construction | 2024 |
| Yeulet Properties Limited | Real estate | 2017 |
| YFS Property Limited | Real estate | 2022 |
| YHW Limited | Hospitality | 2018 |
| Yokegrade Limited | Information & communication | 1974 |
| Yokiro Limited | Professional & scientific | 2023 |
| YOU & New Design Sourcing Limited | Wholesale & retail | 2017 |
| Young's Heating Services Ltd | Construction | 2024 |
| Young’S Property Services Ltd | Real estate | 2020 |
| Your Childcare Solutions Limited | Health & social care | 2012 |
| Your Habitats Ltd | Manufacturing | 2024 |
| YR Group Ltd | Professional & scientific | 2020 |
| Yuan Capital Ltd | Information & communication | 2016 |
| Yura London Limited | Professional & scientific | 2023 |
| Zahmir Regulatory Ltd | Professional & scientific | 2012 |
| ZAK Consultancy Limited | Professional & scientific | 2014 |
| Zayah Media Ltd | Information & communication | 2016 |
| Zayn 1 Holdings Ltd | Financial services | 2024 |
| Zebee Creative Ltd | Professional & scientific | 2022 |
| Zel-Lous Ltd | Other services | 2025 |
| ZEN DC Homes Ltd | Construction | 2023 |
| Zencut AI Solutions Limited | Information & communication | 2024 |
| Zenith Vertex Limited | Wholesale & retail | 2026 |
| Zephyr Horizon Ltd | Professional & scientific | 2024 |
| Zeplin Delivery Limited | Transport & logistics | 2020 |
| Zeyno Deliveries Limited | Transport & logistics | 2020 |
| Zeys 25 Limited | Other services | 2025 |
| Zigzag Solution Limited | Information & communication | 2017 |
| Zorbani Investments Limited | Real estate | 2020 |
| ZS Projects Ltd | Construction | 2020 |