| Yungwave EDU Ltd | Education | 2025 |
| Yusein Ltd | Transport & logistics | 2020 |
| Yusuf's Kebabs Limited | Hospitality | 2020 |
| Yvangeles Limited | Health & social care | 2025 |
| Yvatech Engineering Limited | Information & communication | 2017 |
| YY Golden Ltd | Hospitality | 2024 |
| Z H M Estates Limited | Real estate | 2025 |
| Z Restaurants Ltd | Hospitality | 2020 |
| Z&C Entertainment Ltd | Hospitality | 2024 |
| Z&C Property Holdings Limited | Real estate | 2024 |
| Z&N Spa Ltd | Other services | 2018 |
| Z.Hardiman Brickwork Ltd | Construction | 2018 |
| Z.M Window Cleaning Ltd | Administrative & support | 2025 |
| Z1ON Enterprise Ltd | Information & communication | 2024 |
| Zaariii by LS Ltd | Wholesale & retail | 2026 |
| Zabpoint Limited | Health & social care | 2018 |
| Zafferes Ltd | Hospitality | 2024 |
| Zahar Ltd | Manufacturing | 2025 |
| Zain Birmingham Limited | Administrative & support | 2017 |
| ZAK and Elliot Limited | Information & communication | 2025 |
| ZAK Branch Ltd | Other services | 2017 |
| ZAK Food Store Ltd | Wholesale & retail | 2019 |
| Zaks (UK) Limited | Hospitality | 2013 |
| Zaks Franchising (UK) Limited | Administrative & support | 2025 |
| Zale Services Limited | Professional & scientific | 2018 |
| ZAM Chicken Ltd | Hospitality | 2012 |
| ZAM Lettings Ltd | Real estate | 2021 |
| ZAM Vaping Norwich Ltd | Wholesale & retail | 2024 |
| ZAM ZAM Store Ltd | Wholesale & retail | 2025 |
| Zamcall Norwich Limited | Wholesale & retail | 2019 |
| Zamosc Management Consultants Limited | Professional & scientific | 2017 |
| Zane Comma Ltd | Information & communication | 2023 |
| Zante MK Building Construction Ltd | Construction | 2016 |
| Zany Boutique Ltd | Other services | 2012 |
| Zanzibraai Ltd | Hospitality | 2016 |
| Zaphera Ltd | Hospitality | 2023 |
| ZAR292 Ltd | Other services | 2018 |
| Zara Healthcare Ltd | Administrative & support | 2015 |
| Zarhil Digital Ltd | Information & communication | 2023 |
| Zasby Ltd | Wholesale & retail | 2024 |
| Zasuya Ltd | Hospitality | 2024 |
| Zatu Limited | Wholesale & retail | 2016 |
| ZAU Ltd | Real estate | 2013 |
| Zayn Group Ltd | Administrative & support | 2025 |
| Zayyan Banqueting Limited | Arts & recreation | 2017 |
| Zaza Norwich Ltd | Hospitality | 2024 |
| Zazou Production Works Limited | Information & communication | 2019 |
| ZC Creative Producer Ltd | Information & communication | 2019 |
| ZCJ Investments Limited | Real estate | 2014 |
| ZDQ Investment Ltd | Real estate | 2025 |
| Zebaish Textiles Ltd | Wholesale & retail | 2014 |
| Zebrabuyer Ltd. | Real estate | 2019 |
| Zebrachord 72A Ltd | Real estate | 2022 |
| Zebrachord Ltd | Real estate | 2021 |
| Zebrainvest Ltd. | Real estate | 2019 |
| Zebralive Ltd. | Real estate | 2019 |
| Zebrastay Ltd. | Real estate | 2019 |
| ZEC Property Group Ltd | Financial services | 2025 |
| ZEC Trading Ltd | Financial services | 2025 |
| ZED Global Ltd | Administrative & support | 2020 |
| ZEE Contracting Ltd | Administrative & support | 2018 |
| ZEE Hardware Ltd | Wholesale & retail | 2015 |
| Zefier UK I Limited | Professional & scientific | 2010 |
| Zelah Senior Consulting Limited | Professional & scientific | 2022 |
| Zelos Transport Ltd | Transport & logistics | 2024 |
| ZEN Harmony Ltd | Hospitality | 2025 |
| ZEN Zebra Ltd | Administrative & support | 2023 |
| Zena Aldridge Training & Consultancy Services Ltd | Health & social care | 2022 |
| Zenergy Holdings Ltd | Real estate | 2024 |
| Zengi Barbers Ltd | Other services | 2020 |
| Zenith & Zass Beds Limited | Manufacturing | 2018 |
| Zenith Catering Equipment Limited | Hospitality | 2009 |
| Zenith Holidays Limited | Administrative & support | 2008 |
| Zenith Sports Physiotherapy Ltd | Health & social care | 2026 |
| Zenlo Limited | Wholesale & retail | 2011 |
| Zenmuma Limited | Health & social care | 2017 |
| Zephyr Musical Ventures Limited | Information & communication | 2019 |
| Zera Healthcare Ltd | Administrative & support | 2023 |
| Zerghost Limited | Information & communication | 2025 |
| Zero Carbon Power Limited | Energy | 2011 |
| Zero Pharma & Biotech Ltd | Wholesale & retail | 2022 |
| Zero to Finals Ltd | Education | 2020 |
| Zero UK Limited | Extraterritorial | 2007 |
| Zerofee Limited | Professional & scientific | 2005 |
| Zeropointhouse Ltd | Information & communication | 2020 |
| Zerotaxis Electric Limited | Transport & logistics | 2018 |
| Zest Capital Partners Ltd | Financial services | 2026 |
| Zest Catering Limited | Administrative & support | 2015 |
| Zetta Genomics Limited | Professional & scientific | 2018 |
| Zetter Ltd | Administrative & support | 2019 |
| Zeus Security & Events Limited | Administrative & support | 2025 |
| ZHL Ventures Ltd | Financial services | 2026 |
| Zhora Labs Limited | Information & communication | 2022 |
| ZHW Ltd | Real estate | 2021 |
| ZIB Haulage Ltd | Transport & logistics | 2018 |
| Zielonka Limited | Construction | 2007 |
| Zigzag Ltd | Other services | 2016 |
| Zimbreta Ltd | Professional & scientific | 2020 |
| Zimevolve Logistics Ltd | Professional & scientific | 2025 |
| Zimmoly Informatics Services Ltd | Health & social care | 2012 |