| YOU Were Here First Ltd | Professional & scientific | 2018 |
| You-Asked Solutions Ltd | Administrative & support | 2006 |
| Younesco Limited | Real estate | 2015 |
| Young Gifted and Black Limited | | 2008 |
| Young Horologists Initiative CIC | Education | 2025 |
| Young Miller Limited | Arts & recreation | 2013 |
| Young Trees Education Limited | Education | 2022 |
| Youngerfaces. Co.Uk Limited | Health & social care | 2003 |
| Younghee Limited | Hospitality | 2026 |
| Youngs Property Holdings Limited | Financial services | 2017 |
| Your Best Local Electrician Ltd | Construction | 2026 |
| Your Burnout Coach Ltd | Professional & scientific | 2025 |
| Your Business AI Ltd | Information & communication | 2024 |
| Your Clear Data Ltd | Administrative & support | 2024 |
| Your Designers Limited | Administrative & support | 2015 |
| Your Everyday Solution Limited | Wholesale & retail | 2017 |
| Your Grand Design Limited | Professional & scientific | 2010 |
| Your Home Illustrator Limited | Professional & scientific | 2025 |
| Your Invisible Partner Limited | Administrative & support | 2014 |
| Your Legal GP Limited | Professional & scientific | 2025 |
| Your London Handyman Ltd | Other services | 2024 |
| Your Mind Coach Ltd | Professional & scientific | 2024 |
| Your Mortgage Approved Limited | Financial services | 2018 |
| Your Next Stop Limited | Other services | 2013 |
| Your Prosperity Limited | Financial services | 2018 |
| Your Starttup Advisory Ltd | Professional & scientific | 2024 |
| Your Staycation Limited | Hospitality | 2023 |
| Your Vibrant Life Limited | Education | 2023 |
| Your Will Your Way UK Limited | Other services | 2026 |
| Your Wishes Matter Ltd | Wholesale & retail | 2024 |
| Your World Group Limited | Professional & scientific | 2016 |
| Youra Ltd | Wholesale & retail | 2025 |
| Yourunipath Ltd | Education | 2025 |
| Youth Talent Ltd | Administrative & support | 2021 |
| Yovant Ltd | Information & communication | 2023 |
| Yovlaq Ltd | Wholesale & retail | 2024 |
| YR Experience Limited | Administrative & support | 2025 |
| YR ID UK Limited | Administrative & support | 2009 |
| YR Trading Limited | Wholesale & retail | 2023 |
| YS Construction London Ltd | Construction | 2026 |
| YS Imports Limited | Wholesale & retail | 2025 |
| YS Tiles and Bathrooms Ltd | Wholesale & retail | 2025 |
| YSP Logistics Ltd | Transport & logistics | 2024 |
| YST Estates Limited | Real estate | 2021 |
| YTD Properties Limited | Real estate | 2018 |
| YTI Waqf Ltd | Real estate | 2020 |
| YTS Law Limited | Professional & scientific | 2016 |
| Yu-Serv Limited | Wholesale & retail | 2016 |
| Yudh Commodities Ltd | Wholesale & retail | 2024 |
| Yuga Sushi Ltd | Hospitality | 2022 |
| YUM Eats Limited | Hospitality | 2022 |
| Yume NO Tsuki Limited | Professional & scientific | 2018 |
| Yummy Mummy 247 Ltd | Information & communication | 2022 |
| Yummyco Ltd | Wholesale & retail | 2018 |
| Yurtauk Ltd | Wholesale & retail | 2025 |
| Yusufidrees Ltd | Wholesale & retail | 2026 |
| Yuvilite Limited | Wholesale & retail | 2016 |
| Yuye Marketing Limited | Professional & scientific | 2019 |
| Yvks Holdings Ltd | Real estate | 2021 |
| Yvonne Joyce George Care Services Limited | Health & social care | 2023 |
| YXX Acoustic Guitar Co. Ltd | Wholesale & retail | 2022 |
| YYL Solutions Ltd | Health & social care | 2023 |
| YYZ Investments Limited | Hospitality | 2018 |
| Z & H Holdings Limited | Wholesale & retail | 2022 |
| Z & S Transport Limited | Transport & logistics | 2010 |
| Z &E Halal Meat Ltd | Wholesale & retail | 2015 |
| Z Technologies Ltd | Information & communication | 2024 |
| Z&D Builder Ltd | Construction | 2026 |
| Z&E Investments Limited | Real estate | 2024 |
| Z&S Projects Ltd | Construction | 2015 |
| Z&Z Food Services (Two) Ltd | Hospitality | 2026 |
| Z&Z Food Services Ltd | Hospitality | 2023 |
| Z-Field Estates Ltd | Real estate | 2025 |
| ZA Limited | Professional & scientific | 2004 |
| Zacaria Automotive Ltd | Wholesale & retail | 2024 |
| Zachary Collins Limited | Professional & scientific | 2022 |
| ZAF Enterprises Limited | Real estate | 2022 |
| Zafta Linknet Limited | | 2023 |
| Zafy Enterprises (UK) Limited | Wholesale & retail | 2023 |
| ZAG Construct Ltd | Construction | 2025 |
| Zaha Group Limited | Wholesale & retail | 2025 |
| Zaheer Supermarket Ltd | Wholesale & retail | 2019 |
| Zaherra Property Services Limited | Real estate | 2017 |
| Zahn Services Limited | Information & communication | 2014 |
| Zahra London Limited | Wholesale & retail | 2026 |
| ZAI Plumb Tech Ltd | Construction | 2026 |
| Zaika B Ltd | Wholesale & retail | 2025 |
| Zain Development Ltd | Construction | 2020 |
| Zajac Holdings Limited | Financial services | 2025 |
| ZAK Cars Limited | Administrative & support | 2022 |
| Zakaria Noor Ltd | Wholesale & retail | 2026 |
| Zala Solutions Ltd | Transport & logistics | 2025 |
| Zalmanis Ltd | Wholesale & retail | 2026 |
| Zaloo Properties Ltd | Real estate | 2026 |
| Zaltman Films Limited | Information & communication | 1995 |
| ZAM ZAM Meats and Foods Limited | Wholesale & retail | 2026 |
| Zameen Infrastructure Ltd | Construction | 2015 |
| Zameen Solutions UK (Private) Ltd | Construction | 2025 |
| Zamin Mining Limited | Mining & quarrying | 2023 |
| Zampor Limited | Hospitality | 2019 |