| Zarathustra Ltd | Real estate | 2023 |
| ZAS Yachting Ltd | Extraterritorial | 2024 |
| Zattbuyy Ltd | Wholesale & retail | 2025 |
| Zatz Ltd | Information & communication | 2025 |
| ZAY Groups International Limited | Hospitality | 2026 |
| Zaynan Ltd | Real estate | 2017 |
| Zectech Limited | Information & communication | 2016 |
| ZED Consultancy Ltd | Information & communication | 2024 |
| Zeemal Ltd | Hospitality | 2021 |
| Zefron Limited | Wholesale & retail | 2025 |
| Zellbuy Ltd | Wholesale & retail | 2025 |
| ZEN Havens Ltd | Health & social care | 2023 |
| ZEN Network Solutions Ltd | Professional & scientific | 2019 |
| Zenith Coordination Ltd | Professional & scientific | 2014 |
| Zerobar International Ltd | Wholesale & retail | 2024 |
| Zest Academy Trust | Education | 2012 |
| Zest Gastronomia Ltd | Hospitality | 2001 |
| Zest Lytham Limited | Hospitality | 2024 |
| Zestwave Wholesale Limited | Wholesale & retail | 2025 |
| Zeus Electrical Limited | Construction | 1996 |
| Zevenx Ltd | Manufacturing | 2026 |
| Zhixing Ltd | Hospitality | 2023 |
| Ziggy Products Ltd | Wholesale & retail | 2020 |
| Zillian (Properties) Ltd | Administrative & support | 2015 |
| Zillian Limited | Administrative & support | 2011 |
| Zink Property Management Limited | Administrative & support | 2025 |
| ZLW Engineering Limited | Construction | 2013 |
| ZOE Anastasia Ltd | Administrative & support | 2024 |
| ZOE Gelsthorpe Agencies Ltd | Wholesale & retail | 2021 |
| Zoka Yachting Ltd | Extraterritorial | 2023 |
| Zonex Group Limited | Real estate | 1987 |
| Zorbas Food and Bakery (UK) Limited | Hospitality | 2025 |
| Zorus Limited | Administrative & support | 2017 |
| Zorwix Ltd | Wholesale & retail | 2026 |
| Zozor Consultancy Ltd | Information & communication | 2019 |
| ZPN Consulting Limited | Professional & scientific | 2014 |
| ZT Motors Limited | Wholesale & retail | 2014 |
| Zubaria Beauty, Aesthetics & Training Ltd | Professional & scientific | 2024 |
| Zubaria's Kitchen Ltd | Hospitality | 2024 |
| Zulu Artist Management Agency(Zama) Limited | Professional & scientific | 2025 |
| Zwide Experts Limited | Professional & scientific | 2013 |
| £Aith Property Limited | Real estate | 2017 |