| Yigaz Ltd | Manufacturing | 2024 |
| Yildirim Cargo Ltd | Transport & logistics | 2026 |
| Yildirim Food Catering Ltd | Hospitality | 2021 |
| Yildirim Property Investment Limited | Real estate | 2023 |
| Yildiz Fish & Chips Ltd | Hospitality | 2025 |
| Yildiz Properties Ltd | Real estate | 2025 |
| Yilmaz & Sons Limited | Real estate | 2019 |
| Yilmaz EZE Ltd | Real estate | 2026 |
| Yilmaz Holdings Ltd | Real estate | 2021 |
| Yilmaz Kebab Limited | Hospitality | 2019 |
| YL Properties Ltd | Real estate | 2018 |
| YMR International Ltd | Wholesale & retail | 2024 |
| Ynsp Commerce Ltd | Wholesale & retail | 2026 |
| Yodel UK Limited | Information & communication | 2006 |
| Yoga Dharma Ltd | Health & social care | 2007 |
| Yonja Ltd | Real estate | 2025 |
| Yord Ltd. | Construction | 2017 |
| Yord Property Ltd | Real estate | 2025 |
| York Financial Services and Business Development Limited | Professional & scientific | 2017 |
| YOU ARE Assured Limited | Construction | 2017 |
| YOU ME and Everyone Ltd | Information & communication | 2008 |
| Young Network Ltd | Information & communication | 2007 |
| Young Talent Academy CIC | Administrative & support | 2016 |
| Youngmanconstruction Limited | Construction | 2025 |
| Your Best Self Consultants Ltd | Other services | 2021 |
| Your Biohacker Limited | Wholesale & retail | 2024 |
| Your Place Soho Ltd | Hospitality | 2025 |
| Your Sure Services Ltd. | Construction | 2017 |
| Yourmanwithavanenfield Ltd | Transport & logistics | 2024 |
| Youthworx London Limited | Health & social care | 2019 |
| YPAYMORE2020 Ltd | Wholesale & retail | 2024 |
| YS & Co. Accounting Ltd | Professional & scientific | 2010 |
| YSL Services Limited | Professional & scientific | 2003 |
| YSM Tax Services Ltd | Professional & scientific | 2020 |
| Ysoftsolutions Ltd | Wholesale & retail | 2025 |
| YSS Construction Ltd | Construction | 2024 |
| YSS Developments Ltd | Real estate | 2026 |
| YTA Group Ltd | Financial services | 2025 |
| Ytrax Limited | Information & communication | 2025 |
| Yucel Holding Ltd | Financial services | 2024 |
| YUM YUM Pantry Limited | Hospitality | 2021 |
| Yummies Launceston Ltd | Hospitality | 2024 |
| Yumna Haroon-Mowahed Limited | Health & social care | 2023 |
| Yumyumcusine Limited | Hospitality | 2024 |
| Yunshang (UK) Ltd | Professional & scientific | 2024 |
| Yurtsan Ltd | Professional & scientific | 2026 |
| Yusuf and Liyana Ltd | Extraterritorial | 2021 |
| Yusufian Ltd | Wholesale & retail | 2025 |
| Yutaka Foods Limited | Professional & scientific | 2000 |
| Yuuki Limited | Financial services | 2024 |
| Yuva Property Services Limited | Administrative & support | 2025 |
| Yuval Tsur Properties Ltd | Real estate | 2019 |
| Yuvam Kebab Limited | Hospitality | 2025 |
| YUZ Properties Limited | Real estate | 2020 |
| YZ Construction Ltd | Water & waste | 2026 |
| YZ Group Ltd | Real estate | 2025 |
| YZ Oriental Panda Ltd | Hospitality | 2022 |
| YZN Consultancy Ltd | Professional & scientific | 2025 |
| Z Plus Design Ltd | Construction | 2019 |
| Z Reynolds 1973 Holdings Ltd | Professional & scientific | 2023 |
| Z&Z Electricians Ltd | Construction | 2025 |
| Z.A. Surveying & Consulting Limited | Other services | 2019 |
| Z.Arc Limited | Professional & scientific | 2000 |
| ZA ALB Ltd | Wholesale & retail | 2026 |
| ZAA Constructing & Consultancy Limited | Professional & scientific | 2025 |
| ZAC Services Limited | Administrative & support | 2016 |
| Zai's House Ltd | Financial services | 2017 |
| ZAK Winston's Holistic Movement Limited | Education | 2016 |
| ZAL Group Limited | Hospitality | 2020 |
| Zani Construction Ltd | Construction | 2020 |
| Zara Electrical Ltd | Manufacturing | 2021 |
| ZAW Tiling Limited | Construction | 2025 |
| Zawj Limited | Administrative & support | 2025 |
| ZAY Rayan Care Limited | Health & social care | 2018 |
| Zayker Ltd | Real estate | 2025 |
| Zaza Meat Wholesale Ltd | Wholesale & retail | 2026 |
| ZB Painting and Landscaping Services Ltd | Construction | 2025 |
| ZBL Sawicki Ltd | Construction | 2015 |
| ZC Cleaning Limited | Administrative & support | 2026 |
| Zebi Construction Limited | Construction | 2024 |
| Zebi Davis Limited | Professional & scientific | 2016 |
| Zeco Entertainment Ltd | Professional & scientific | 2025 |
| ZEE Best German Doner Ltd | Hospitality | 2019 |
| ZEE HCA Venture Ltd | Health & social care | 2025 |
| Zeeb Healthcare Limited | Administrative & support | 2024 |
| Zeel Tech Limited | Wholesale & retail | 2025 |
| Zefyr Digital Limited | Professional & scientific | 2024 |
| Zehra Limited | Real estate | 2024 |
| Zehrasultan Ltd | Hospitality | 2019 |
| Zein's Barber Ltd | Other services | 2023 |
| ZEK Services Ltd | Construction | 2025 |
| ZEL Yapi Ltd | Construction | 2020 |
| Zelal Properties Ltd | Real estate | 2025 |
| Zemy Trade Ltd | Wholesale & retail | 2019 |
| ZEN Garden 4U Ltd | Administrative & support | 2025 |
| ZEN Hair&Beauty Ltd | Other services | 2022 |
| ZEN Lighting Ltd | Construction | 2021 |
| ZEN Terpz Limited | Wholesale & retail | 2025 |
| Zenith Digi Ltd | Wholesale & retail | 2025 |
| Zenith Homecare Ltd | Health & social care | 2025 |