| Wyke Green Golf Club (1996) Limited | Arts & recreation | 1996 |
| Wyndham Court (Freehold) Limited | Households | 2021 |
| X Care Ltd | Health & social care | 2023 |
| X Plan Design Ltd | Real estate | 2023 |
| Xentrik TV Ltd | Information & communication | 2010 |
| Xeris Security Ltd | Administrative & support | 2023 |
| Xint Business Limited | Professional & scientific | 2017 |
| Xint Investments Limited | Real estate | 2016 |
| Xpress Refinishing Solutions International Limited | Financial services | 2023 |
| YA Fragrances Ltd | Wholesale & retail | 2025 |
| Yaanky Ltd | Hospitality | 2026 |
| Yablock Resources Ltd | Construction | 2025 |
| Yakondo Ltd | Information & communication | 2020 |
| Yani Services Ltd | Administrative & support | 2017 |
| Yaqoot Media Ltd | Manufacturing | 2017 |
| Yarty Construction Ltd | Construction | 2026 |
| YCA London Ltd | Construction | 2020 |
| YJ Fire Solutions Ltd | Construction | 2026 |
| YK Electrical and Contractors Limited | Manufacturing | 2015 |
| YK Richmond Contractors Ltd | Construction | 2024 |
| YLS Trading Limited | Wholesale & retail | 2018 |
| YMS Technical Services Ltd | Professional & scientific | 2015 |
| Yokuworld Ltd | Wholesale & retail | 2025 |
| Your Food and Wine Ltd | Wholesale & retail | 2025 |
| Your Ghar Limited | Real estate | 2025 |
| Your Golden Path Limited | Wholesale & retail | 2026 |
| Your Perfect Space Ltd | Construction | 2015 |
| Yourette Ltd | Administrative & support | 2023 |
| Yousourcedit Ltd | Wholesale & retail | 2022 |
| Yoyo International Travel Limited | Administrative & support | 2015 |
| Yrpharma Ltd | Health & social care | 2019 |
| Yves Frey Diamonds Limited | Wholesale & retail | 2007 |
| Z N H Traders Limited | Wholesale & retail | 2025 |
| Z&C and Associates Limited | Administrative & support | 2018 |
| Zaavi Limited | Wholesale & retail | 2025 |
| Zabuli Limited | Administrative & support | 2023 |
| Zadjali Limited | Real estate | 2018 |
| Zafron Global Ltd | Hospitality | 2026 |
| Zaidi Property Investments Limited | Real estate | 2024 |
| Zaktiza Ltd | Information & communication | 2012 |
| Zedled Repair Limited | Other services | 2019 |
| Zedtek Communications Limited | Information & communication | 2014 |
| ZEE Transport Solution Ltd | Extraterritorial | 2020 |
| Zeerise Ltd | Wholesale & retail | 2026 |
| Zero Waste Club Ltd | Manufacturing | 2017 |
| Ziora Diamonds Limited | Extraterritorial | 2025 |
| Ziroc Ltd | Administrative & support | 2021 |
| ZKG International Limited | Information & communication | 2025 |
| ZN Estates Ltd | Real estate | 2022 |
| Zola Productions Ltd | Information & communication | 2023 |
| Zonda House Ltd | Hospitality | 2025 |
| Zoom Sales UK Ltd | Other services | 2018 |
| Zorixa Ltd | Wholesale & retail | 2025 |
| ZS Chauffeurs Ltd | Transport & logistics | 2022 |
| Zsthetics Ltd | Health & social care | 2019 |
| ZTQ Service Ltd | Information & communication | 2025 |
| Zz.Expressive Ltd | Wholesale & retail | 2026 |