| Wheels Excellence Ltd | Wholesale & retail | 2024 |
| White and Bright Tooth Ltd | Health & social care | 2026 |
| White Crystal Interiors Ltd | Administrative & support | 2020 |
| White Kanvas Capital Ltd | Financial services | 2021 |
| White Oak Construction Ltd | Construction | 2016 |
| White Plus Limited | Other services | 2023 |
| Whitehot Creative Limited | Professional & scientific | 2011 |
| Whitney Property Consultants Ltd | Construction | 2019 |
| Whois Data Limited | Information & communication | 2014 |
| Whois Trading Limited | Professional & scientific | 2014 |
| Whole Health Maternity Limited | Health & social care | 2025 |
| WHY Here Ltd | Other services | 2024 |
| Wideskill Limited | Extraterritorial | 2002 |
| Wigman Way Limited | Real estate | 2017 |
| Wigmores Properties Limited | Financial services | 2012 |
| Wilbury Bodyshop MOT & Service Centre Limited | Other services | 2009 |
| Wild Bloom Design Landscaping Ltd | Administrative & support | 2025 |
| Wilde Hill Limited | Wholesale & retail | 2022 |
| Wildrose Trading Ltd | Wholesale & retail | 2025 |
| Wildwood Validation Limited | Information & communication | 2018 |
| Wilkestock Festivals Limited | Administrative & support | 2016 |
| Willbecks Properties Ltd | Real estate | 2021 |
| Willbray Limited | Manufacturing | 2007 |
| Willbroad Healthcare Limited | Other services | 2018 |
| Willey Spiros Enterprizes Limited | Arts & recreation | 1985 |
| William Gerard Electrical Ltd | Construction | 2026 |
| Willowdene Freeholders Ltd | Administrative & support | 2017 |
| Willowgate Management Company Limited | Households | 1999 |
| Willows Workshop Ltd | Manufacturing | 2016 |
| Wills Electrical Services Ltd | Manufacturing | 2021 |
| Willshine Recruitment Limited | Health & social care | 2022 |
| Wilrhys Limited | Wholesale & retail | 2024 |
| Wilson Medical Ltd | Wholesale & retail | 2021 |
| Wilx Music Limited | Arts & recreation | 2019 |
| Winaid Ltd | Health & social care | 2025 |
| Windiacre Developments Ltd | Real estate | 2021 |
| Windmill Chase(Block D)Management Company Limited | Households | 1985 |
| Window Care Herts Ltd | Construction | 2010 |
| Windstep Ltd | Manufacturing | 2025 |
| Winney Ltd | Construction | 2022 |
| Winrom Solutions Ltd | Administrative & support | 2024 |
| Winside Solutions Limited | Information & communication | 2014 |
| Winstons Supply Company Limited | Wholesale & retail | 2001 |
| Winters Lane Luxury Cat Hotel Ltd | Hospitality | 2020 |
| Winwood Capital Limited | Financial services | 2014 |
| Wise Scaffold Services Ltd | Construction | 2014 |
| Wixams Management Company Limited | Households | 2013 |
| Wizardly Digital Ltd | Information & communication | 2024 |
| WJ Heating Ltd | Energy | 2021 |
| WJS Capital Holdings Limited | Financial services | 2020 |
| WKR Ltd | Wholesale & retail | 2010 |
| WMS Underfloor Heating Limited | Construction | 2014 |
| Woburn Contracts Ltd | Construction | 2016 |
| Wolf Brand Experience Limited | Administrative & support | 2013 |
| Women's Engineering Society | Administrative & support | 1919 |
| Wonder Women Publishing Limited | Information & communication | 2012 |
| Wonderland Creative Limited | Information & communication | 2014 |
| Wood and Stone Floors Limited | Construction | 2023 |
| Wood House Media Group Ltd | Information & communication | 2022 |
| Woodbury Hill Construction Limited | Construction | 2018 |
| Woodhall House Residents Association Limited | Households | 1995 |
| Woodhouse 1 (Cirencester) Management Company Limited | Households | 1988 |
| Woodlands Garden Suppliers Ltd | Wholesale & retail | 2026 |
| Woodlands Music Ltd | Other services | 2022 |
| Woodlands Records Ltd | Arts & recreation | 2021 |
| Woodlands Studio Limited | Other services | 2020 |
| Woodpecker London Ltd | Manufacturing | 2024 |
| Woodside Close Limited | Real estate | 2021 |
| Woolff Gallery Limited | Arts & recreation | 2000 |
| Woolmer Environmental Services Ltd | Administrative & support | 2019 |
| Woolmer Pest Control Limited | Other services | 1999 |
| Woolners Way (Stevenage) Management Company Limited | Households | 2007 |
| Workplace Change Limited | Administrative & support | 2014 |
| Workwell Fabrications Limited | Administrative & support | 2003 |
| World Class Care and Support Services Ltd | Health & social care | 2025 |
| World Food Holdings Limited | Hospitality | 2018 |
| World Packaging Limited | Financial services | 2010 |
| Worldfloor Retail Limited | Manufacturing | 2009 |
| Worldwide Metal Limited | Wholesale & retail | 2025 |
| WOW Homes Ltd | Real estate | 2021 |
| Wreckspeditions Dive Charters Limited | Transport & logistics | 2017 |
| Wrestletalk Digital Ltd | Other services | 2022 |
| Wrightade Limited | Construction | 2016 |
| Wrimes Cosmetics Ltd | Manufacturing | 2014 |
| Wrimes Properties Ltd | Real estate | 2020 |
| Write Imagination Ltd | Information & communication | 2024 |
| Write Recruit Ltd | Professional & scientific | 2021 |
| WSF Construction Ltd | Construction | 2019 |
| WSG Finance Limited Partnership | | 2003 |
| Wunderkammer Entertainment Ltd | Arts & recreation | 2016 |
| Wura's Kitchen Limited | Hospitality | 2025 |
| Wyah Ltd | Information & communication | 2019 |
| Wyatt Installations Limited | Construction | 2026 |
| WYE Services Limited | Other services | 2024 |
| Wyldr Ltd | Manufacturing | 2026 |
| Xabeo Limited | Administrative & support | 2008 |
| Xander Enterprises Limited | Real estate | 2024 |
| XAR Ltd | Wholesale & retail | 2012 |
| Xenka Solutions Limited | Information & communication | 2022 |
| Xglobal Investment Ltd | Financial services | 2021 |