| Xenith Consortium Ltd | Education | 2025 |
| Xenium Limited | Financial services | 1972 |
| Xenophon Limited | Financial services | 2014 |
| XL Property Ventures Limited | Construction | 2017 |
| XO Express Tailoring UK Limited | Other services | 2010 |
| Xpedite Employee Ownership Trustee Limited | Financial services | 2024 |
| Xpedite Group of Companies Limited | Manufacturing | 2004 |
| Xpedite Holdings Limited | Manufacturing | 2019 |
| Y-Mobility Limited | Professional & scientific | 2019 |
| YAA Flooring Ltd | Construction | 2025 |
| Yacht Marketing (Southern) Limited | | 1920 |
| Yama Yoga Hub Ltd | Arts & recreation | 2019 |
| Yardstick Design Ltd | Administrative & support | 2024 |
| Yatta Ltd | Information & communication | 2008 |
| Yearproject Property Management Limited | Households | 1991 |
| Yellow 47 Limited | Administrative & support | 2009 |
| Yellow Group Limited | Financial services | 2025 |
| Yellow Snail Consulting Ltd | Information & communication | 2014 |
| Yellowlees Business Services Limited | Professional & scientific | 2017 |
| Yellowstone Consulting Ltd | Professional & scientific | 2018 |
| Yerbury Homes Limited | Construction | 2019 |
| YES Mate Productions Ltd | Administrative & support | 2020 |
| Yeti Properties Ltd | Real estate | 2018 |
| Yeti Trading and Holding Company Limited | Information & communication | 2026 |
| Yewshore Ltd | Wholesale & retail | 2013 |
| Yfizz Media Ltd | Information & communication | 2021 |
| Yipso Accountancy Services Ltd | Professional & scientific | 2006 |
| YKF Properties Limited | Real estate | 2023 |
| YM Investments Limited | Real estate | 2020 |
| Ymca Brunel Group | Hospitality | 1999 |
| Yngr Design Ltd | Professional & scientific | 2022 |
| Yoga and Wild Wellness Ltd | Wholesale & retail | 2021 |
| Yoga Kula Hub Ltd. | Arts & recreation | 2018 |
| Yoga Kula Limited | Arts & recreation | 2014 |
| Yogakave Ltd | Arts & recreation | 2022 |
| Yogaliving Limited | Health & social care | 2003 |
| Yogeemu Limited | Information & communication | 2011 |
| Yondrr Group Limited | Manufacturing | 2017 |
| York Mews (Bath) Management Limited | Households | 2026 |
| York Place Capital Limited | Administrative & support | 2005 |
| York Place Foundation | Education | 2002 |
| Yorkshire in Cider Trading Limited | Hospitality | 2016 |
| Yorkshire Signature Lettings Limited | Real estate | 2026 |
| Youlovebrand.Co.Uk Limited | Construction | 2009 |
| Young Carers Development Trust | Education | 2011 |
| Young Explorers LLP | | 2023 |
| Youngearly Limited | Hospitality | 1996 |
| Youngs Construction (Bath) Ltd | Construction | 2011 |
| Your Backpack Limited | Professional & scientific | 2020 |
| Your Design (Bristol) Limited | Professional & scientific | 2010 |
| Your Design Group Ltd | Construction | 2025 |
| Your Eco Construction Ltd | Professional & scientific | 2016 |
| Yourgymguide Ltd | Information & communication | 2025 |
| Youth Connect South West | Health & social care | 2019 |
| YPK Entertainment Ltd | Information & communication | 2017 |
| YRN Consultancy Limited | Hospitality | 2016 |
| Ystwyth Ventures Limited | Information & communication | 2020 |
| YTL Arena Holdings Limited | Financial services | 2021 |
| YTL Brabazon CP28 Limited | Real estate | 2025 |
| YTL Brabazon D6 Limited | Real estate | 2025 |
| YTL Brabazon E Limited | Real estate | 2025 |
| YTL Brabazon E1 Limited | Real estate | 2025 |
| YTL Brabazon P2 P3 Limited | Real estate | 2025 |
| YTL Brabazon R2S Ltd | Real estate | 2026 |
| YTL Construction (UK) Limited | Construction | 2023 |
| YTL Corporation (UK) PLC | Professional & scientific | 1927 |
| YTL Developments (UK) Limited | Construction | 2016 |
| YTL Enterprises Limited | Real estate | 2025 |
| YTL Homes Ltd | Real estate | 2016 |
| YTL Infrastructure (UK) Limited | Construction | 2024 |
| YTL Land and Property (UK) Ltd | Financial services | 2016 |
| YTL Live (Operations) Limited | Real estate | 2025 |
| YTL Live (Property) Limited | Financial services | 2021 |
| YTL Living Limited | Real estate | 2024 |
| YTL M&E Services (UK) Ltd | Construction | 2026 |
| YTL Places Limited | Extraterritorial | 2016 |
| YTL Plant and Fleet Solutions (UK) Limited | Construction | 2024 |
| YTL Property Holdings (UK) Limited | Financial services | 2015 |
| YTL SA 1 Limited | Real estate | 2023 |
| YTL Solutions Limited | Manufacturing | 2026 |
| YTL Student Limited | Real estate | 2024 |
| YTL Utilities (UK) Limited | Financial services | 2001 |
| Yuille V Ltd | Professional & scientific | 2025 |
| Yuviyukt Estate Ltd | Real estate | 2024 |
| Z & F Developments Ltd | Construction | 2021 |
| Z House Development Limited | Real estate | 2018 |
| Z House One Limited | Real estate | 2021 |
| Z House Two Limited | Real estate | 2021 |
| Z-Estima Limited | Professional & scientific | 2013 |
| Zaff Supplies Ltd | Hospitality | 2020 |
| Zahara Systems Ltd | Information & communication | 2017 |
| Zairerealm Limited | Real estate | 2023 |
| ZAK & Foods Ltd | Hospitality | 2023 |
| Zaki Food Limited | Hospitality | 2026 |
| Zambezi Trading Limited | Hospitality | 2019 |
| Zander Trading Limited | Wholesale & retail | 2021 |
| Zany Ants Limited | Information & communication | 2007 |
| ZAP Power Ltd | Professional & scientific | 2023 |
| Zaytoun & Qahwa Limited | Hospitality | 2025 |
| ZEC Music Ltd | Information & communication | 2012 |