| Yums 2009 Limited | Real estate | 2020 |
| Yusuf Medical Limited | Health & social care | 2014 |
| Yvonne Elizabeth Murray Ltd | Extraterritorial | 2024 |
| Z Cleaning Service Ltd | Administrative & support | 2025 |
| Z&S Whippy Ltd | Manufacturing | 2024 |
| ZA Thrive Limited | Wholesale & retail | 2025 |
| Zac’S Gutters Ltd | Construction | 2020 |
| Zafar Enterprise Limited | Wholesale & retail | 2023 |
| Zaff Cars Ltd | Transport & logistics | 2023 |
| Zafron Eastbourne Limited | Hospitality | 2025 |
| Zaf’Ron Ltd | Hospitality | 2022 |
| Zagrus Ltd | Real estate | 2026 |
| Zair Technics Ltd | Manufacturing | 2023 |
| Zaltan Group of Companies Limited | Wholesale & retail | 2025 |
| Zamzam Halal Crawley Ltd | Wholesale & retail | 2019 |
| Zara&Fabi Limited | Health & social care | 2018 |
| Zareeya Ltd | Education | 2026 |
| Zari Contemporary Indian Cuisine Limited | Hospitality | 2021 |
| ZAS Prestige Ltd | Wholesale & retail | 2026 |
| Zassi Ltd | Wholesale & retail | 2026 |
| Zbizglobal Ltd | Wholesale & retail | 2022 |
| Zbjzbj Ltd | Wholesale & retail | 2025 |
| ZCB Resolutions Limited | Public administration | 2026 |
| Zebedee Services Ltd | Information & communication | 2020 |
| Zebra Park Ltd | Transport & logistics | 2026 |
| ZEE Parking Ltd | Other services | 2020 |
| Zeeconsults Ltd | Professional & scientific | 2025 |
| Zeiyad Ltd | Health & social care | 2022 |
| ZEN Alpha Limited | Administrative & support | 2026 |
| Zenitel Centre of Excellence UK Limited | Information & communication | 1981 |
| Zenitel Trustees Limited | Professional & scientific | 2024 |
| Zenithal Cosmetics Ltd | Wholesale & retail | 2025 |
| Zenrise Projects Ltd | Real estate | 2026 |
| Zentralabs Ltd | Wholesale & retail | 2026 |
| Zephyr Engineering Limited | Extraterritorial | 2020 |
| Zepra Ltd | Wholesale & retail | 2022 |
| Zero Maintenance Group Ltd | Water & waste | 2024 |
| Zesk Limited | Administrative & support | 2025 |
| Zest Designs Limited | Information & communication | 1994 |
| Zetez Solutions Limited | Information & communication | 2018 |
| Zeze Dinos Ltd | Hospitality | 2023 |
| ZH Enterprises Ltd | Hospitality | 2025 |
| Zhoi Consulting Ltd | Health & social care | 2025 |
| ZIM Airport Transfers Ltd | Transport & logistics | 2018 |
| ZIP Properties Group Ltd | Construction | 2021 |
| ZMD Parcel Delivery Ltd | Transport & logistics | 2025 |
| Zodiac Allstars | Arts & recreation | 2015 |
| Zodiac Allstars Trading Ltd | Wholesale & retail | 2015 |
| Zodiac Software Limited | Information & communication | 2009 |
| Zodwa's Ltd | Health & social care | 2016 |
| Zoghayyer Limited | Wholesale & retail | 2019 |
| Zojobel Ltd | Information & communication | 2016 |
| Zolt Couriers Limited | Transport & logistics | 2016 |
| Zoltan SOS Surgical Assisting Ltd | Health & social care | 2022 |
| Zorro Property Investments Ltd | Real estate | 2026 |
| ZS Construction Limited | Manufacturing | 2016 |
| ZSB Planning Consultants Limited | Professional & scientific | 2011 |
| Zulo Design Ltd | Construction | 2018 |
| Zyea Ltd | Hospitality | 2025 |
| ZZ Deals Ltd | Wholesale & retail | 2025 |
| £&£ Limited | Information & communication | 2021 |