| YELLOWBIRD888 Limited | Hospitality | 2025 |
| Yells Yard Management Company Ltd | Households | 2025 |
| Yelp Cctv Limited | Administrative & support | 2018 |
| Yemyen Limited | Health & social care | 2023 |
| Yeokom Engineering Ltd | Construction | 2017 |
| Yesda Limited | Administrative & support | 2023 |
| Yestem Project Community Interest Company | Information & communication | 2026 |
| Yetik Ltd | Hospitality | 2025 |
| Yetik's Kebab and Fish Ltd | Hospitality | 2025 |
| YEW Tree Investments Limited | Real estate | 1995 |
| Yildiz Hair Care Ltd | Other services | 2020 |
| Ymtt Trading and Services Ltd | Health & social care | 2018 |
| YO! Sushi Swindon Ltd | Hospitality | 2023 |
| YO! Sushi Trowbridge Ltd | Hospitality | 2023 |
| YO! Sushi Yate Ltd | Hospitality | 2023 |
| Yo&Pav Ltd | Administrative & support | 2024 |
| Yogasanskriti CIC | Other services | 2024 |
| Yorizon UK Ltd | Information & communication | 2026 |
| Yoska Consulting Ltd | Information & communication | 2025 |
| Yottalogica Limited | Professional & scientific | 2020 |
| YOU CAN Fitness UK Limited | Arts & recreation | 2021 |
| Youfindit Limited | Wholesale & retail | 2023 |
| Young Choices Limited | Health & social care | 2020 |
| Younique Travel Adventures Ltd | Administrative & support | 2003 |
| Your Best Finance (UK) Ltd | Professional & scientific | 2018 |
| Your Business Efficient Ltd | Extraterritorial | 2023 |
| Your Business Rooms Ltd | Real estate | 2019 |
| Your Future Your Money Limited | Financial services | 2014 |
| Your Go-To Home Support Ltd | Administrative & support | 2024 |
| Your Image, OUR Business Ltd | Manufacturing | 2023 |
| Your Local Window Cleaner Limited | Administrative & support | 2025 |
| Your Logo Limited | Wholesale & retail | 2010 |
| Your People Team Limited | Professional & scientific | 2026 |
| Your Personal Installer Ltd | Construction | 2020 |
| Your Pocket Assistant Limited | Wholesale & retail | 2021 |
| Your Sport Global Limited | Information & communication | 2015 |
| Your Story Counselling Ltd | Education | 2024 |
| Yourtravelclub Ltd | Administrative & support | 2021 |
| Youth Adventure Trading Ltd | Health & social care | 2016 |
| Youth Adventure Trust | Health & social care | 1993 |
| Yowie Tool Limited | Professional & scientific | 2020 |
| Ypdt Leisure Limited | Arts & recreation | 1990 |
| YPG Associates Ltd | Administrative & support | 2019 |
| Ypostirixi Ltd | Health & social care | 2016 |
| YS7 Ltd | Manufacturing | 2024 |
| Yummy Scrummies Ltd | Hospitality | 2024 |
| Yunus Catering Limited | Wholesale & retail | 2013 |
| Yunus Food Services Limited | Wholesale & retail | 2023 |
| Yurcal Solutions Ltd | Administrative & support | 2024 |
| Yuyuma Collection Limited | Wholesale & retail | 2022 |
| YW Solutions Limited | Information & communication | 2017 |
| YWT Engineering and Technology Ltd | Manufacturing | 2020 |
| Z Property Estates Ltd | Real estate | 2025 |
| Z Property Ltd | Real estate | 2018 |
| Z&Z Optical Clinic Ltd | Professional & scientific | 2024 |
| Z2 Hakka Limited | Hospitality | 2024 |
| Z2 Limited | Information & communication | 2010 |
| ZA3 Limited | Public administration | 2018 |
| Zabka Supermarket 1235 Ltd | Wholesale & retail | 2026 |
| Zabka Supermarket Swindon Ltd | Wholesale & retail | 2025 |
| ZAC Motors Ltd | Wholesale & retail | 2025 |
| Zafar Iqbal Ltd | Wholesale & retail | 2025 |
| Zafrek Care Ltd | Health & social care | 2020 |
| Zaia Design Ltd | Wholesale & retail | 2019 |
| Zakopane Supermarket Ltd | Wholesale & retail | 2018 |
| Zamba Shop UK Ltd | Wholesale & retail | 2025 |
| Zana Laundry Ltd | Other services | 2023 |
| Zana Properties Swindon Ltd | Real estate | 2024 |
| Zanpure Limited | Information & communication | 2011 |
| Zantanite Group Ltd | Real estate | 2024 |
| Zapp Active Limited | Information & communication | 2019 |
| Zarawa UK Ltd | Wholesale & retail | 2022 |
| Zaroor Limited | Wholesale & retail | 2024 |
| ZAY Accountants Ltd | Professional & scientific | 2025 |
| Zaytoun Trade Ltd | Wholesale & retail | 2024 |
| Zazzy Print Ltd | Manufacturing | 2021 |
| ZB Emea Finance UK 1 Ltd | Financial services | 2019 |
| ZB UK Group Holdings Limited | Financial services | 2019 |
| ZB UK Plant Holdings Limited | Financial services | 2023 |
| Zeal Wealth Ltd | Professional & scientific | 2024 |
| Zebra Solutions Limited | Professional & scientific | 2011 |
| Zedis Limited | Transport & logistics | 2009 |
| ZEE Communications Ltd | Information & communication | 2015 |
| ZEE Modest Collections Ltd | Wholesale & retail | 2024 |
| Zeemee Bros Ltd | Wholesale & retail | 2025 |
| Zeka Transport Ltd | Transport & logistics | 2019 |
| ZEL Tutoring Ltd | Education | 2025 |
| ZEN Ventures Club Ltd | Administrative & support | 2024 |
| Zenbox Ltd | Wholesale & retail | 2017 |
| Zenez Ltd | Education | 2022 |
| Zenithedge Ltd | Wholesale & retail | 2026 |
| Zenntro Ltd | Wholesale & retail | 2026 |
| Zeno's Cafe Limited | Wholesale & retail | 2025 |
| Zentone Ltd | Wholesale & retail | 2025 |
| Zentra Capital Ltd | Professional & scientific | 2025 |
| Zentroo Limited | Wholesale & retail | 2025 |
| Zeolite Trade Limited | Construction | 2018 |
| Zero Offers Ltd | Information & communication | 2023 |
| Zero One Movement Ltd | Health & social care | 2019 |
| Zerra Limited | Manufacturing | 2025 |