| WT Partnership International Limited | Professional & scientific | 1988 |
| WT Partnership Trustees Limited | Administrative & support | 2023 |
| WT Partnership-Group | Professional & scientific | 1984 |
| Wtce Limited | Professional & scientific | 2013 |
| Wybak Limited | Professional & scientific | 2025 |
| Wyfold Court Mansion House Management Company Limited | Households | 1998 |
| Wylder Gardens Ltd | Administrative & support | 2023 |
| Wyle COP Management Company Limited | Households | 2005 |
| Wyllweb Limited | Information & communication | 2014 |
| WZW Limited | Real estate | 2021 |
| X36 Property Management Ltd | Real estate | 2022 |
| X9 NGU Investment Limited | Other services | 2025 |
| Xand Technical Solutions Ltd | Information & communication | 2025 |
| Xanz Ltd | Transport & logistics | 2025 |
| Xash Tech Limited | Information & communication | 2025 |
| Xavier Olivier Monvil Services Limited | Construction | 2019 |
| Xaymaca Shop Ltd | Wholesale & retail | 2021 |
| XC Entertainment Ltd | Hospitality | 2025 |
| Xcentrik Services Ltd | Administrative & support | 2020 |
| Xcentrik Solutions Ltd | Education | 2021 |
| Xclusive Meets Xcellence Limited | Construction | 2018 |
| Xcon Technologies Limited | Information & communication | 2025 |
| XCV Group Ltd | Real estate | 2023 |
| XEN Ltd | Information & communication | 2025 |
| Xerographic International Ltd | Wholesale & retail | 2009 |
| Xforge Exhibition Solutions Ltd | Real estate | 2023 |
| Xilo.Inkedit Ltd | Arts & recreation | 2025 |
| XIN Hyatt Limited | Hospitality | 2019 |
| Xing TAT Trading Company Limited | Wholesale & retail | 2005 |
| Xinyi Media Ltd | Wholesale & retail | 2024 |
| XK Consultants Ltd | Professional & scientific | 2020 |
| Xmax Tech Ltd | Information & communication | 2022 |
| XMX London Limited | Construction | 2018 |
| XO Fashion Limited | Wholesale & retail | 2026 |
| XPC Transport Ltd | Transport & logistics | 2025 |
| Xpert Consultancy Limited | Other services | 2016 |
| Xpert Excellence Ltd | Wholesale & retail | 2023 |
| Xpert Supplies Ltd | Wholesale & retail | 2022 |
| Xperts Consultancy Limited | Administrative & support | 2011 |
| Xpleesit Collections Ltd | Manufacturing | 2025 |
| Xpress GSM Services Ltd | Wholesale & retail | 2018 |
| Xpress Night Ltd | Manufacturing | 2019 |
| Xquizit Learners Ltd | Education | 2022 |
| Xstro Estates Limited | Real estate | 2014 |
| Xstro Investments Limited | Real estate | 2006 |
| Xstro Nash Limited | Real estate | 2021 |
| Xstro Properties Limited | Real estate | 2006 |
| Xtrak Limited | Information & communication | 2023 |
| Xtralarge Global Agritourism Ltd | Agriculture & fishing | 2025 |
| Xtrapolate Limited | Information & communication | 2011 |
| Xtreme Koncepts Ltd | Professional & scientific | 2025 |
| Xxviii Ltd | Wholesale & retail | 2012 |
| XYZ Entertainment Limited | Information & communication | 2013 |
| XYZ Mail Order Ltd | Wholesale & retail | 2022 |
| Y & N Limited | Wholesale & retail | 2015 |
| Y Architecture Limited | Extraterritorial | 2024 |
| Y LOU and M Akunjee Gynaecology Services LLP | | 2025 |
| Y T Y Catering Ltd | Hospitality | 2024 |
| Y Werddon Management Limited | Households | 2006 |
| Y&K 17 Ltd | Construction | 2017 |
| Y&M Enterprises Ltd | Hospitality | 2012 |
| Y.E.S Education Service Ltd | Education | 2025 |
| Y.Shimada Ltd | Other services | 2018 |
| Y3K (Europe) Limited | Wholesale & retail | 2000 |
| Y3N Limited | Information & communication | 2022 |
| YA Building Maintenance Ltd | Construction | 2023 |
| YA Tech Ltd | Information & communication | 2025 |
| YA YA Cards Limited | Wholesale & retail | 2021 |
| Yaaaej Ltd | Wholesale & retail | 2025 |
| Yaadu Travel Services Ltd | Administrative & support | 2024 |
| Yaaker Limited | Financial services | 2024 |
| Yaalini Ilankumaran Photography Ltd | Professional & scientific | 2025 |
| Yadpro Ltd | Information & communication | 2025 |
| Yahn Enterprise Ltd | Wholesale & retail | 2025 |
| Yahweh Living Way City Central Ltd | Other services | 2025 |
| Yahweh's Kingdom Ministry Ltd | Other services | 2020 |
| Yajman IT Consultancy Ltd | Information & communication | 2018 |
| YAM YAM Bubble Waffles Limited | Wholesale & retail | 2016 |
| YAN QI Xing HE Media Ltd | Wholesale & retail | 2025 |
| Yardmasters Ltd | Administrative & support | 2025 |
| Yaseen Property Services Ltd | Real estate | 2002 |
| Yash Investments Ltd | Real estate | 2018 |
| Yasins Constructions Ltd | Construction | 2025 |
| Yasir Properties Ltd | Real estate | 2021 |
| Yass-Gas Ltd | Construction | 2024 |
| Yasuke Goods Ltd | Wholesale & retail | 2026 |
| Yathuraa Ltd | Health & social care | 2024 |
| Yati Properties Limited | Real estate | 2024 |
| Yatizeel Limited | Wholesale & retail | 2020 |
| Yavne Ltd | Professional & scientific | 2015 |
| Yaye.Diallo Ltd | Health & social care | 2023 |
| Yayladere(Xolxol) Restaurants Limited | Wholesale & retail | 2023 |
| YCL (UK) Limited | Wholesale & retail | 2012 |
| YCZ Autos Limited | Wholesale & retail | 2022 |
| YD Catering Ltd | Hospitality | 2023 |
| YD Investments Group Ltd | Financial services | 2018 |
| YD Morleys Fried Chicken Ltd | Hospitality | 2020 |
| Yeabu (London) Limited | Administrative & support | 2013 |
| Yeataghub Ltd | Real estate | 2023 |
| YED Catering Ltd | Administrative & support | 2016 |