| Wine Roots Trails Ltd | Administrative & support | 2025 |
| Wink Aesthetics Kent Ltd | Health & social care | 2024 |
| Winland Commercial Ltd | Real estate | 2023 |
| Winners Property Solutions Ltd | Real estate | 2021 |
| Winning Workx Ltd | Professional & scientific | 2025 |
| Winter 01224 Limited | Other services | 2015 |
| Winterflood Business Services Limited | Administrative & support | 2026 |
| Wisdom Hospice Charity | Health & social care | 1982 |
| Wisdom Hospice Support | Wholesale & retail | 2012 |
| Wisdom Sanctuary Limited | Administrative & support | 2012 |
| Wise Teaching Solutions Ltd | Professional & scientific | 2019 |
| Wisenet Services Limited | Wholesale & retail | 2025 |
| Wisestay Ltd | Households | 2025 |
| Wistransport Ltd | Transport & logistics | 2021 |
| Wizzigroup Limited | Information & communication | 2024 |
| Wizzirole Ltd | Information & communication | 2025 |
| WJ Garden Care Ltd | Administrative & support | 2024 |
| WM Michael Ltd | Professional & scientific | 2024 |
| WMG Davies Ltd | Real estate | 2021 |
| Wntt Limited | Wholesale & retail | 2019 |
| Wolf Building Services Ltd | Construction | 2025 |
| Wolf Drinks Ltd | Wholesale & retail | 2025 |
| Wolfgang Cohesive Services Limited | Professional & scientific | 2019 |
| Wombat Developments Ltd | Real estate | 2022 |
| Women in Business Events CIC | Administrative & support | 2021 |
| Women in Management TOP50 UK Ltd | Other services | 2025 |
| Wonder Nails & Co Ltd | Other services | 2022 |
| Wood & Sons Construction Ltd | Construction | 2020 |
| Woodbridge Management & Consultancy Limited | Professional & scientific | 2026 |
| Wooden GUN Ltd | Professional & scientific | 2018 |
| Woodfield Residents Company Limited | Households | 2025 |
| Woodrow Project Management Ltd | Construction | 2026 |
| Woodrush Estates Ltd | Construction | 2020 |
| Woods Drylining & Property Services Ltd | Construction | 2023 |
| Woods Medical Limited | Health & social care | 2021 |
| Woods Solutions Limited | Construction | 2011 |
| Woolkett Group Ltd | Financial services | 2026 |
| Woolmington Consultant Engineers Ltd | Construction | 2007 |
| Work Reconstructed Ltd | Professional & scientific | 2024 |
| Workstar Solutions Limited | Administrative & support | 2025 |
| World of London Ltd | Manufacturing | 2017 |
| World Treasures Ltd | Wholesale & retail | 2021 |
| Worldverse Estates Ltd | Real estate | 2025 |
| Worldview 2000 Limited | Real estate | 1997 |
| Worth Construction Ltd | Construction | 2019 |
| WOW Eats UK Ltd | Hospitality | 2025 |
| WOW Sleep Ltd | Extraterritorial | 1994 |
| WPR Logistics Limited | Construction | 2011 |
| Wraith Engineering Services Limited | Construction | 1997 |
| Wrap Kitchen Ltd | Hospitality | 2025 |
| Wrayzin Property Partners Ltd | Real estate | 2025 |
| Wreck-A-Mended Auto Repairs Limited | Wholesale & retail | 2013 |
| Wren Commercials Ltd | Wholesale & retail | 2017 |
| Wrights Fencing Limited | Construction | 2005 |
| WSB Administration Services LLP | | 2012 |
| WSD Enviro Ltd | Professional & scientific | 2023 |
| WT Advisory Ltd | Extraterritorial | 2024 |
| Wthreads Ltd | Wholesale & retail | 2025 |
| Wymo Ltd | Information & communication | 2021 |
| X Bakestation X Ltd | Manufacturing | 2025 |
| X-Connection Solutions Ltd | Information & communication | 2025 |
| X76 Ltd | Wholesale & retail | 2019 |
| Xcelant Limited | Financial services | 2017 |
| Xerim Holdings Ltd | Financial services | 2023 |
| XLN Construction Ltd | Construction | 2014 |
| XLN Group Ltd | Professional & scientific | 2021 |
| XLR Powakradle Limited | Manufacturing | 2022 |
| XO Construction Ltd | Construction | 2019 |
| XO Homes and Co Limited | Real estate | 2019 |
| XO Homes Ltd | Construction | 2018 |
| Xodus Healthcare Limited | Other services | 2013 |
| XOX Coatings Ltd | Construction | 2025 |
| Xpolyma Recycling Limited | Water & waste | 2024 |
| XRB Consulting Ltd | Professional & scientific | 2021 |
| XY Group Ltd | Professional & scientific | 2020 |
| XY LED Ltd | Administrative & support | 2015 |
| Xy.Live Ltd | Administrative & support | 2020 |
| Y&I Building Ltd | Construction | 2025 |
| Y2S Consulting Ltd | Professional & scientific | 2020 |
| Yabsley Holdings Limited | Professional & scientific | 2004 |
| Yabsley Investments Limited | Transport & logistics | 2015 |
| Yali Real Estate Ltd Ltd | Households | 2023 |
| Yanall Limited | Professional & scientific | 2008 |
| Yanee Motors Limited | Manufacturing | 2026 |
| Yangs WOK Strood Ltd | Hospitality | 2026 |
| YAZ786 Ltd | Health & social care | 2026 |
| YEP Residential Limited | Real estate | 2019 |
| Yepi Limited | Information & communication | 2025 |
| Yinkabelle Ltd | Wholesale & retail | 2015 |
| Yirli Client Services Ltd | Real estate | 2020 |
| Yjpropertyinvestment Ltd | Real estate | 2025 |
| YMU Services Limited | Financial services | 2017 |
| YNK Property Renovations Ltd | Real estate | 2025 |
| Yorkshire Cooperage Services Limited | Extraterritorial | 2018 |
| YOU Matter Community Project CIC | Health & social care | 2025 |
| Youdig Ltd | Administrative & support | 2016 |
| Young's Antiques Ltd | Wholesale & retail | 2018 |
| Younique Designs Ltd | Administrative & support | 2007 |
| Your Bridal Besties UK Ltd | Other services | 2026 |
| Your Cruise Holiday Ltd | Administrative & support | 2023 |