| WYN Management Ltd | Financial services | 2025 |
| Wyndham Road Management Co. Limited | Households | 2004 |
| WZ Holdings Limited | Arts & recreation | 2026 |
| X Motorcycles Sales & Repairs Ltd | Wholesale & retail | 2019 |
| Xanders Healthcare Solutions Limited | Real estate | 2023 |
| Xaso Ltd | Professional & scientific | 2017 |
| Xceedall Spaces Limited | Real estate | 2023 |
| Xcel Electrical Services Ltd | Construction | 2020 |
| Xeedr Ltd | Administrative & support | 2024 |
| XEN Group Limited | Health & social care | 2024 |
| Xendorasity Ltd | Information & communication | 2026 |
| Xenia Aidonopoulou Projects Ltd | Arts & recreation | 2021 |
| Xenta Ltd | Households | 2024 |
| Xhus Export Ltd | Wholesale & retail | 2024 |
| Xiilio Ltd | Professional & scientific | 2026 |
| XL Global Education Ltd | Information & communication | 2024 |
| XLM Ltd | Hospitality | 2016 |
| XLV1 Administrative Limited | Professional & scientific | 2023 |
| Xoticxtac Ltd | Wholesale & retail | 2024 |
| Xperience Franchising Limited | Real estate | 1989 |
| Xpress Response Support Limited | Construction | 2014 |
| XPT Agents Limited | Administrative & support | 2025 |
| Xstream Plumbing and Heating Ltd | Administrative & support | 2017 |
| Xtrawatt Ltd | Professional & scientific | 2026 |
| Xtreme Gear Ltd. | Wholesale & retail | 2014 |
| Y2 Healthcare Ltd | Health & social care | 2022 |
| Yaawingss Limited | Wholesale & retail | 2026 |
| Yachtcoat Ltd | Manufacturing | 2023 |
| YAD CI Group Ltd | Financial services | 2026 |
| Yadah Global Fellowship Ltd | Other services | 2024 |
| Yanis Bacila Ltd | Construction | 2019 |
| Yapton Pharmacy Limited | Health & social care | 2012 |
| Yardgate Limited | Professional & scientific | 2002 |
| Yaresa Limited | Real estate | 2024 |
| Yari Window Blind Ltd | Manufacturing | 2020 |
| Yarmouth Court Management Limited | Households | 2005 |
| Yarra Solutions Limited | Information & communication | 2026 |
| Yarrowood Ltd | Real estate | 2023 |
| Yass Trading Ltd | Hospitality | 2025 |
| Yatesmain Ltd | Education | 2025 |
| Yavuz Gocer Hairdresser Ltd | Other services | 2021 |
| Ybymotors Limited | Wholesale & retail | 2016 |
| Ycuk Limited | Financial services | 2022 |
| YD LAB Ltd | Manufacturing | 2024 |
| Years to Come Ltd | Agriculture & fishing | 2024 |
| Yelling Performance Ltd | Arts & recreation | 2005 |
| Yellowbox Communications Ltd | Manufacturing | 2003 |
| YER Eyes Limited | Health & social care | 2024 |
| YES Treatment Ltd | Health & social care | 2020 |
| Yessave Ltd | Wholesale & retail | 2014 |
| YHT Plumbing & Heating Ltd | Construction | 2026 |
| Yilmaz Barber Limited | Other services | 2020 |
| YK Electrical Contractors Ltd | Construction | 2016 |
| YKT Limited | Professional & scientific | 2018 |
| Ylie Services Ltd | Information & communication | 2016 |
| YMS Beauty Limited | Other services | 2020 |
| Ymsouthbourne Limited | Hospitality | 2025 |
| YO Wireless Global Ltd | Information & communication | 2013 |
| Yogavedaukhub Ltd | Education | 2019 |
| Yoke IT Solutions Ltd | Information & communication | 2024 |
| Yokyok Limited | Wholesale & retail | 2020 |
| York House (Bournemouth) Limited | Households | 1991 |
| Yosa Botanicals Ltd | Wholesale & retail | 2021 |
| YOU Hair Design Ltd | Other services | 2012 |
| Youcan Properties Limited | Extraterritorial | 2018 |
| Young Bros Holdings Ltd | Financial services | 2024 |
| Youngs Retro Design Ltd | Wholesale & retail | 2023 |
| Your Choice Cleaning With Care Ltd | Administrative & support | 2011 |
| Your Choice Contract Cleaning Ltd | Administrative & support | 2021 |
| Your Eco Gardener Ltd | Administrative & support | 2021 |
| Your Future NOW Ltd | Professional & scientific | 2019 |
| Your Future Planning Ltd | Professional & scientific | 2023 |
| Your Go to Services Ltd | Construction | 2025 |
| Your Italiano Chef Limited | Hospitality | 2018 |
| Your Lawn UK Ltd | Administrative & support | 2025 |
| Your MAN With a Van (BCP) Ltd | Transport & logistics | 2024 |
| Your Plumber Limited | Construction | 2009 |
| Your Project Solved Limited | Construction | 2024 |
| Your Roofer Dorset Ltd | Construction | 2020 |
| Your Slimming Clinic Ltd | Health & social care | 2020 |
| Your Space Carpentry and Construction Limited | Manufacturing | 2021 |
| Yourlife Management Services Limited | Real estate | 2010 |
| Youseeme Ltd | Wholesale & retail | 2025 |
| Youthchoice CIC | Other services | 2025 |
| YPI Limited | Real estate | 2013 |
| YS Engineering & Management Consulting Limited | Professional & scientific | 2017 |
| Ystwyth Limited | Information & communication | 2018 |
| YTP Ltd | Professional & scientific | 2026 |
| Yulan Inn Limited | Hospitality | 2019 |
| Yumi Sushi Ltd | Hospitality | 2025 |
| YUN Properties Limited | Real estate | 2011 |
| Yunique Milk Tea Ltd | Hospitality | 2019 |
| Yuzuandco LLP | | 2026 |
| Z & S Railway Ltd | Construction | 2025 |
| Z D Medicals Limited | Health & social care | 2013 |
| Z&J Merali Publishing Ltd | Wholesale & retail | 2021 |
| Z.W.O Power Limited | Construction | 2025 |
| Z3 Sports Ltd | Wholesale & retail | 2024 |
| Zaara Traders Ltd | Wholesale & retail | 2024 |
| Zahadi Limited | Transport & logistics | 2024 |