| Yalla Koronbaa Limited | Hospitality | 2021 |
| Yappsinn Ltd | Hospitality | 2014 |
| Yates & Co Construction Ltd | Construction | 2025 |
| Yates Square Management Limited | Households | 2006 |
| YDH Developments Ltd | Real estate | 2024 |
| YDJ Investments Ltd | Financial services | 2024 |
| Yeaton Energy Limited | Mining & quarrying | 2018 |
| Yellow Rose Homes Limited | Real estate | 2015 |
| Yellow Tree Studio Ltd | Administrative & support | 2024 |
| Ynyslas Property Limited | Construction | 2013 |
| Yockleton Growers Ltd | Agriculture & fishing | 2015 |
| Yoda Worldwide Limited | Financial services | 2023 |
| Yogaspirit Limited | Education | 2004 |
| Yoghurt Maker Limited | Hospitality | 2023 |
| Yolo Driving School UK Limited | Administrative & support | 2016 |
| Yonder Property Ltd | Real estate | 2025 |
| York Road Management Limited | Households | 2002 |
| Yorkshire Picture House Limited | Real estate | 2024 |
| YOU Beauty Salon Ltd | Other services | 2022 |
| Your Land Partner Ltd | Construction | 2018 |
| Yourgreen Ltd | Wholesale & retail | 2020 |
| Yours South Lynn Home 1 Limited | Administrative & support | 2006 |
| Yours South Lynn Home 2 Limited | Administrative & support | 2006 |
| Yours South Lynn Home 3 Limited | Administrative & support | 2013 |
| Yours South Lynn Home 4 Limited | Real estate | 2015 |
| Yours South Lynn Neighbourhood Limited | Administrative & support | 2006 |
| Yourview Landscapes Ltd | Administrative & support | 2021 |
| Youth Leisure Company Limited | Arts & recreation | 2017 |
| Yucca Promotions Limited | Hospitality | 2001 |
| Yumkin Limited | Extraterritorial | 2014 |
| Z for Zulu Limited | Information & communication | 2013 |
| Z J Coatings Ltd | Manufacturing | 2023 |
| Zami Care Limited | Health & social care | 2012 |
| Zanzi Beauty Limited | Wholesale & retail | 2017 |
| ZAR HR Ltd | Professional & scientific | 2021 |
| Zefi Ground Works Ltd | Construction | 2023 |
| Zelton Consulting Ltd | Professional & scientific | 2011 |
| ZEN Lets (Shropshire) Ltd | Real estate | 2025 |
| Zencop Plumbing Limited | Construction | 2025 |
| Zenith Getaways Ltd | Administrative & support | 2023 |
| Zeno AI Ltd | Information & communication | 2025 |
| Zenserve IT Limited | Information & communication | 2010 |
| Zero Waste in a Box Limited | Water & waste | 2011 |
| Zfmansha Ltd | Health & social care | 2021 |
| ZHIVKO123 Limited | Hospitality | 2020 |
| Ziglen Limited | Professional & scientific | 2012 |
| ZIN Brothers Limited | Hospitality | 2019 |
| Zinc E-Consulting Ltd | Information & communication | 2011 |
| Zodiac Games Limited | Manufacturing | 2019 |
| ZOST16 Limited | Wholesale & retail | 2021 |
| Zotair Ltd | Wholesale & retail | 2019 |
| Zuba Solar Energy Ltd | Professional & scientific | 2025 |
| Zumba Shropshire Ltd | Professional & scientific | 2011 |
| ZUU Ltd | Information & communication | 2023 |
| Zuxo Ltd | Wholesale & retail | 2024 |
| Zwanenberg Food Group UK Limited | Manufacturing | 1971 |
| Zyla Studio Ltd | Extraterritorial | 2023 |
| “THE Greenhouse” Company Ltd | Hospitality | 2018 |