| Woof Self Wash Ltd | Other services | 2025 |
| Woolf&Co Limited | Administrative & support | 2006 |
| Woolway & Co Limited | Information & communication | 2010 |
| Words Europe Limited | Professional & scientific | 1999 |
| Work From Home Limited | Real estate | 2021 |
| Workforce Facilities Ltd | Construction | 2016 |
| Workforce Metrics Limited | Information & communication | 2009 |
| Workready Training C.I.C. | Administrative & support | 2026 |
| Worksite Technology Limited | Information & communication | 2001 |
| World Copyright Limited | Professional & scientific | 2023 |
| World Gallery Limited | Information & communication | 2023 |
| World Photo Gallery Limited | Information & communication | 2023 |
| World Photographic Gallery Limited | Information & communication | 2023 |
| World Travel PR Limited | Professional & scientific | 2005 |
| World Travellers UK Limited | Administrative & support | 2000 |
| Worldia Ltd | Administrative & support | 2023 |
| Worldwide Apartments.Co.Uk (London) Limited | Hospitality | 2021 |
| Worldwide Aviation and Tourism Ltd | Administrative & support | 2020 |
| Worldxchange Foundation | Professional & scientific | 2023 |
| Worthing Trading Limited | Administrative & support | 2015 |
| Wpforge Ltd | Information & communication | 2018 |
| WQ Construction Services Limited | Construction | 2012 |
| WR Tenet Limited | Information & communication | 2021 |
| WTS Tyres Richmond Limited | Wholesale & retail | 2014 |
| Wunderk Limited | Extraterritorial | 2026 |
| WW Energy Partners Limited | Professional & scientific | 2024 |
| WW Medical Facilities Limited | Construction | 2015 |
| WW Waste Ltd | Water & waste | 2025 |
| WWC Global Ltd | Financial services | 2026 |
| WWC Holding Ltd | Financial services | 2026 |
| WWC Partners Ltd | Financial services | 2026 |
| Xand IQ Ltd | Information & communication | 2025 |
| Xandra Murii TM Ltd | Construction | 2024 |
| XIN Limited | Extraterritorial | 2014 |
| Xpedition Air Limited | Administrative & support | 2015 |
| Xperiensys Limited | Information & communication | 2015 |
| Xptz Limited | Professional & scientific | 2002 |
| Xroute Ltd | Transport & logistics | 2026 |
| XS Clean Services Limited | Administrative & support | 2023 |
| Xtendd Technology Ltd | Information & communication | 2023 |
| Xygen Ltd | Information & communication | 2024 |
| Xylera Ltd | Information & communication | 2023 |
| Y Ltd | Information & communication | 1998 |
| Y S Comms Limited | Professional & scientific | 2013 |
| YA Services Ltd | Wholesale & retail | 2017 |
| Yabgu Ltd | Wholesale & retail | 2025 |
| YAD Moss SKI Club Ltd | Arts & recreation | 1995 |
| Yale Limited | Construction | 2021 |
| Yaman 2024 Ltd | Hospitality | 2024 |
| Yanghe International Ltd | Wholesale & retail | 2024 |
| Yapkim Construction Chemicals Ltd | Wholesale & retail | 2024 |
| Yaraah Ltd | Health & social care | 2020 |
| Yatagan Limited | Professional & scientific | 2022 |
| Yellow Duck Property Limited | Real estate | 2023 |
| Yellow Pelican Consulting Ltd | Professional & scientific | 2021 |
| Yesta Brands Ltd | Manufacturing | 2023 |
| YGN8 Limited | Hospitality | 2023 |
| Yhuk Holding 1 Ltd | Financial services | 2025 |
| Yhuk Holding 2 Ltd | Financial services | 2025 |
| YIL Ltd | Hospitality | 2023 |
| YKM Enterprises Ltd | Wholesale & retail | 2016 |
| Yokohama and York Limited | Transport & logistics | 2009 |
| Yolo Inc 1 Limited | Wholesale & retail | 2013 |
| Yolo Inc Limited | Wholesale & retail | 2014 |
| Yordale Property Limited | Real estate | 2024 |
| Yorhold Limited | Professional & scientific | 1991 |
| York Property Partners Ltd | Real estate | 2018 |
| Yorkshire Clay Company Ltd | Agriculture & fishing | 2023 |
| Yorkshire Country Holidays Limited | Hospitality | 2005 |
| Yorkshire Dales Bookkeeping Services Ltd | Professional & scientific | 2023 |
| Yorkshire Gameshire Ltd | Administrative & support | 2019 |
| Yorkshire Pizza Restaurants Limited | Hospitality | 2025 |
| Yorkshire Property Compliance Ltd | Professional & scientific | 2026 |
| Yorkshire Residential Holdings Ltd | Real estate | 2025 |
| Yorkshire Shepherdess Ltd | Information & communication | 2018 |
| Yorkshire Wedding Barn Limited | Real estate | 2014 |
| Yormanor Limited | Real estate | 2025 |
| YOU and ME Brands Ltd | Wholesale & retail | 2025 |
| YOU Need a Vicky TOO Ltd | Other services | 2025 |
| Young's Provisions Ltd | Hospitality | 2017 |
| Youngs Roofing and Building Solutions Ltd | Construction | 2020 |
| Your Freedom First Ltd | Real estate | 2023 |
| Your Music Network Limited | Extraterritorial | 2016 |
| YOUR2050 Limited | Professional & scientific | 2015 |
| YOUR2050 Software Limited | Information & communication | 2018 |
| Youth Nation Soccer School Ltd | Arts & recreation | 2020 |
| Yufei London Ltd | Wholesale & retail | 2024 |
| Yugen Mono London Ltd | Professional & scientific | 2026 |
| Yuko Satoh Limited | Professional & scientific | 2014 |
| Yuma Sushi Limited | Hospitality | 2013 |
| YY Services Ltd | Wholesale & retail | 2018 |
| YZ1 Limited | Information & communication | 2001 |
| Z Corp Export Limited | Wholesale & retail | 2018 |
| Zagros Climate Control Ltd | Extraterritorial | 2017 |
| Zahh UK Limited | Financial services | 2018 |
| Zahlberg LLP | | 2017 |
| Zanc Travel Group Limited | Administrative & support | 2000 |
| Zard Ltd | Professional & scientific | 2024 |
| Zarian Architects Limited | Professional & scientific | 2015 |
| Zebra Property Management North East 2 Ltd | Real estate | 2025 |