| Yerrill Murphy LLP | | 2009 |
| YES WE Buy Ltd | Wholesale & retail | 2020 |
| Yeti Adventures Ltd | Administrative & support | 2026 |
| Yhnell Investments Ltd | Real estate | 2022 |
| YIL Engineering Limited | Professional & scientific | 2014 |
| YJH Properties Ltd | Real estate | 2025 |
| YJX Limited | Wholesale & retail | 2020 |
| Ynysddu Car Sales Ltd | Wholesale & retail | 2019 |
| Ynysddu MOT Test Centre Ltd | Wholesale & retail | 2019 |
| Yobi Caerleon Limited | Hospitality | 2019 |
| Yobi Holdings Limited | Financial services | 2021 |
| Yobi Limited | Hospitality | 2022 |
| Yoganjali Consultancy Services Ltd | Information & communication | 2017 |
| Yondur Ltd | Information & communication | 2022 |
| Yoof Group Ltd | Information & communication | 2020 |
| Yoof Media Limited | Information & communication | 2023 |
| Yoof Talent Limited | Professional & scientific | 2023 |
| York Chambers Ltd | Households | 2022 |
| York House Property Limited | Real estate | 2023 |
| York Place Letting Limited | Real estate | 2000 |
| Yorkshire Imaging Limited | Health & social care | 2013 |
| Yorkshire Skills Academy Limited | Information & communication | 2011 |
| YOU Glow Aesthetics Clinic Ltd | Health & social care | 2023 |
| Your Car Group Ltd | Wholesale & retail | 2017 |
| Your London Limited | Real estate | 2012 |
| Your Table Catered Ltd | Hospitality | 2024 |
| Yourbid Limited | Real estate | 2024 |
| Yours Bikes & Home Services Limited | Construction | 2025 |
| Youth Radio Rocks Ltd | Information & communication | 2023 |
| YPB Properties Ltd | Real estate | 2025 |
| Ystudio Limited | Professional & scientific | 2013 |
| Ystwyth Court Management Company Limited | Hospitality | 1992 |
| Ystwyth Medical Services Limited | Health & social care | 2014 |
| YT Cheung Limited | Professional & scientific | 2020 |
| Yudigital Ltd | Information & communication | 2024 |
| Yuhan Catering Limited | Hospitality | 2024 |
| Yukon BE Oarsome Ltd | Administrative & support | 2022 |
| Yule Forensic Medico Legal Services Limited | Health & social care | 2008 |
| YUM YUM Convenience Store Ltd | Wholesale & retail | 2025 |
| Yummie's Catering Ltd | Extraterritorial | 2011 |
| Yummy GD Limited | Hospitality | 2019 |
| Yurexpress Ltd | Transport & logistics | 2017 |
| YUSRA24 Property UK Ltd | Real estate | 2026 |
| Yvonne Morgan Ltd | Health & social care | 2022 |
| Yyds Food Limited | Wholesale & retail | 2024 |
| Z & B Design and Research Consultancy Ltd | Professional & scientific | 2025 |
| Z&M Capital Ltd. | Financial services | 2025 |
| ZA Hairdresser Ltd | Other services | 2020 |
| Zach Mercer Ltd | Arts & recreation | 2019 |
| Zahid Limited | Transport & logistics | 2017 |
| Zain Gate Ltd | Hospitality | 2016 |
| ZAK & SON Properties Ltd | Real estate | 2025 |
| Zak's Buy & Sell Ltd | Other services | 2023 |
| Zale Auto Ltd | Wholesale & retail | 2022 |
| Zale Ltd | Transport & logistics | 2019 |
| ZAM Store Ltd | Wholesale & retail | 2026 |
| ZAM ZAM HH Ltd | Wholesale & retail | 2022 |
| ZAM ZAM Market Ltd | Wholesale & retail | 2025 |
| Zamabhele Investments Ltd | Health & social care | 2019 |
| Zamzam 288GB Ltd | Wholesale & retail | 2024 |
| Zanies Ltd | Construction | 2015 |
| Zappi Interior Contracts Limited | Professional & scientific | 2018 |
| Zari Hussain Ltd | Wholesale & retail | 2021 |
| Zaza Risca Ltd | Hospitality | 2025 |
| Zazi Limited | Information & communication | 2001 |
| ZB Corp Ltd | Wholesale & retail | 2021 |
| Zeal Tax (Midlands) Limited | Professional & scientific | 2022 |
| Zeal Tax (Newport) Limited | Professional & scientific | 2017 |
| Zeal Tax (R&D) Limited | Professional & scientific | 2020 |
| Zebra and Associates Ltd. | Transport & logistics | 2018 |
| ZED Haulage Ltd | Transport & logistics | 2021 |
| Zeds Real Estate Limited | Real estate | 2024 |
| Zeetoys Ltd | Wholesale & retail | 2023 |
| Zelador Limited | Wholesale & retail | 2015 |
| Zelus Performance Company Ltd | Wholesale & retail | 2026 |
| ZEN Bookkeeping Ltd | Professional & scientific | 2018 |
| ZEN Spa Ltd | Other services | 2014 |
| Zendas Digital Ltd | Professional & scientific | 2023 |
| Zenith Electronics Design Limited | Professional & scientific | 2006 |
| Zephyr Omega Business Solutions Limited | Information & communication | 2012 |
| Zephyrus Marine Limited | Transport & logistics | 2021 |
| Zeraafat Ltd | Wholesale & retail | 2018 |
| Zero Balancing UK Limited | Education | 2018 |
| Zero Flux Limited | Hospitality | 2024 |
| Zero Marketing Services Ltd | Professional & scientific | 2020 |
| Zest Accountants and Business Advisors Limited | Professional & scientific | 2015 |
| Zeus Barber Ltd | Real estate | 2017 |
| Zeus Enterprises 2025 Ltd | Hospitality | 2025 |
| ZG Consultancy Limited | Construction | 2021 |
| Zhazym Ltd | Wholesale & retail | 2025 |
| Zhou Blade Services Ltd | Manufacturing | 2024 |
| Zhou.Pearce Properties Limited | Real estate | 2025 |
| Zhubin Kurd Barbers Ltd | Other services | 2026 |
| Ziggs Enterprises Limited | Health & social care | 2021 |
| Zilan (Newport) Barber Ltd | Other services | 2025 |
| Zilan Homes Ltd | Real estate | 2025 |
| Zincu Limited | Professional & scientific | 2017 |
| Zion House Management Limited | Households | 2010 |
| Ziqara Ltd | Wholesale & retail | 2026 |
| Zirzuri Ltd | Health & social care | 2022 |