| Wumbei Nabil Management Ltd | Professional & scientific | 2023 |
| Wushi Limited | Health & social care | 2025 |
| Wyatt PMO Ltd | Professional & scientific | 2025 |
| Wynters Investments Limited | Real estate | 2021 |
| X Machina Ltd | Manufacturing | 2019 |
| X7 Properties Ltd | Real estate | 2020 |
| Xanex Limited | Information & communication | 2011 |
| Xceledge Ltd | Professional & scientific | 2024 |
| Xcellfirm Limited | Health & social care | 2022 |
| Xclout Ltd | Information & communication | 2026 |
| Xclusive Designs Limited | Manufacturing | 2009 |
| Xdeal Nordic Ltd | Wholesale & retail | 2020 |
| Xela Logistics Ltd | Transport & logistics | 2021 |
| Xenyth.Ai Limited | Information & communication | 2023 |
| Xieite Limited | Construction | 2021 |
| Xlence Ltd | Construction | 2025 |
| Xmart Soft Ltd | Hospitality | 2009 |
| XMR Haulage&Utility Ltd | Transport & logistics | 2025 |
| Xpress Ride Limited | Transport & logistics | 2026 |
| XTA Solutions Ltd | Administrative & support | 2011 |
| Xtreme Commercial Services Ltd | Construction | 2026 |
| Xtreme Oasis Property Services Limited | Real estate | 2026 |
| Xtremeway Outdoors Ltd | Information & communication | 2017 |
| XXL Transport Ltd | Transport & logistics | 2019 |
| Xyntrix Ltd | Information & communication | 2025 |
| Y & B Takeaway Limited | Hospitality | 2017 |
| Y B Homes Ltd | Real estate | 2021 |
| Y N Construction Ltd | Construction | 2019 |
| Y@Rd Limited | Hospitality | 2021 |
| YA Pombe Ltd | Wholesale & retail | 2025 |
| Yadhashem Limited | Health & social care | 2026 |
| Yahtsuri Limited | Wholesale & retail | 2021 |
| Yakmun UK Limited | Health & social care | 2013 |
| Yanker Ltd | Transport & logistics | 2025 |
| Yardshift Ltd | Construction | 2026 |
| Yarnist Ltd | Wholesale & retail | 2023 |
| Yaro Joinery Limited | Construction | 2026 |
| YAS & D Homes Ltd | Real estate | 2025 |
| YAYA24 Ltd | Transport & logistics | 2024 |
| Yazici Ltd | Wholesale & retail | 2020 |
| Yellow Brick RD Community Interest Company | Education | 2024 |
| Yellow Oasis Ltd | Wholesale & retail | 2022 |
| Yelma Limited | Hospitality | 2022 |
| Yemintimacy Incorporated Ltd. | Wholesale & retail | 2015 |
| Yemric Resources Limited | Professional & scientific | 2013 |
| Yenstone Group Ltd | Administrative & support | 2026 |
| Yenstone Walling and Landscaping Ltd | Administrative & support | 2019 |
| Yeti Grip Limited | Other services | 2022 |
| Yetty Logistics Ltd | Wholesale & retail | 2020 |
| Yexit (Industries) Ltd | Information & communication | 2016 |
| YHS Medical Group Limited | Health & social care | 2025 |
| Yield Financial Limited | Financial services | 2016 |
| Yield Group Limited | Real estate | 2023 |
| Yieldmark Products Ltd | Wholesale & retail | 2026 |
| Yildiz Jewelry Ltd | Manufacturing | 2020 |
| Yinnie Encore Ltd | Health & social care | 2024 |
| Ylli Logistics Ltd | Transport & logistics | 2026 |
| YN Food and Beverage Limited | Hospitality | 2026 |
| Yoga Union Limited | Arts & recreation | 2020 |
| Yoldas Ozan Ltd | Wholesale & retail | 2014 |
| Yombol Medical Personnel Ltd | Health & social care | 2021 |
| Yophie Clothing Ltd | Wholesale & retail | 2021 |
| Yoprotection Ltd | Financial services | 2020 |
| York House RTM Company Limited | Households | 2015 |
| Yotovski Gardeners Limited | Transport & logistics | 2016 |
| YOU Could Venture Limited | Professional & scientific | 2025 |
| YOU SEE What YOU Know Limited | Health & social care | 2026 |
| Youkar Ltd | Administrative & support | 2024 |
| Young Concern Trust | Health & social care | 1988 |
| Your Box Ltd | Extraterritorial | 2024 |
| Your Community Sports and Leisure Limited | Arts & recreation | 2021 |
| Your Confidante Ltd | Other services | 2015 |
| Your Local Honey Co UK Ltd | Hospitality | 2024 |
| Your Local Tree & Hedge Cutting Services Ltd | Administrative & support | 2025 |
| Your Stairs Enfield Ltd | Manufacturing | 2018 |
| Your Vision Events Planning Ltd | Professional & scientific | 2022 |
| Your Wellness Studio Limited | Other services | 2025 |
| Yours Supply Limited | Wholesale & retail | 2025 |
| Yourwarehousedeals UK Limited | Wholesale & retail | 2025 |
| Youth Create Does Parties Ltd | Other services | 2020 |
| Yrop Properties Limited | Real estate | 2019 |
| YS Medical Services Ltd | Health & social care | 2025 |
| YSC Mortgage Solutions Ltd | Financial services | 2017 |
| YSC Property Ltd | Real estate | 2025 |
| YSM Accountants Limited | Professional & scientific | 2026 |
| YTS Consulting Ltd | Professional & scientific | 2013 |
| Ytuk Ltd | Other services | 2019 |
| Yummy Sushi Ltd | Wholesale & retail | 2025 |
| Yusufcan Ltd | Wholesale & retail | 2019 |
| Yvonne Bourne Conveyancing Ltd | Professional & scientific | 2023 |
| YYT Properties Ltd | Real estate | 2022 |
| Z&A Invoke Solutions Ltd | Public administration | 2018 |
| Z.Ehdego Limited | Health & social care | 2023 |
| Zaac & TEE Ltd | Health & social care | 2019 |
| Zabi International Limited | Administrative & support | 2017 |
| Zabi Limited | Hospitality | 2019 |
| Zack Williams Ltd | Real estate | 2022 |
| ZAH Global Ltd | Wholesale & retail | 2026 |
| Zaharia Ltd | Transport & logistics | 2015 |
| ZAK Learning Ltd | Education | 2020 |