| Wild Booch Ltd | Manufacturing | 2024 |
| Wild Oaks Early Learning Centre Ltd | Education | 2021 |
| Wildmoor (Castle Street) Ltd | Real estate | 2012 |
| Wildmoor (Cricklade Street) Limited | Real estate | 2005 |
| Wildmoor (Crowborough) Limited | Real estate | 1997 |
| Wildmoor (Kings Head Hotel, Cirencester) Limited | Real estate | 2003 |
| Wildmoor Estate Management Limited | Professional & scientific | 2019 |
| Wildmoor Investments Limited | Real estate | 1995 |
| Wildmoor Limited | Professional & scientific | 2019 |
| Wildtrack Nordic Ltd | Administrative & support | 2025 |
| Wiley and Wynn Ltd | Wholesale & retail | 2024 |
| Will R Long Ltd | Manufacturing | 2025 |
| Williams Renewables Limited | Professional & scientific | 2011 |
| Willivan Property Holdings Limited | Real estate | 2021 |
| Willow Bridge Farm Limited | Agriculture & fishing | 2022 |
| Willyweather (UK) Limited | Professional & scientific | 2017 |
| Wilson Mgmt Ltd | Information & communication | 2025 |
| Wiltshire Gynaecology Services Limited | Health & social care | 2015 |
| Winchcombe Communications Limited | Professional & scientific | 2022 |
| Windrush Care Ltd | Health & social care | 2015 |
| Winson Farms Limited | Agriculture & fishing | 1953 |
| Winston's Reclaimed Bricks Ltd | Wholesale & retail | 2023 |
| Winstone One Limited | Real estate | 2025 |
| Wintermann Search & Selection Limited | Administrative & support | 2000 |
| Wintermanns Limited | Administrative & support | 2007 |
| Wire Technologies Limited | Wholesale & retail | 2018 |
| Wise Estate Planning Ltd. | Professional & scientific | 2015 |
| Wldt Ltd | Other services | 2025 |
| Wmprop Group NO2 Limited | Real estate | 2023 |
| Wmprop Holdings Limited | Real estate | 2024 |
| Wmprop Subsidiary Limited | Real estate | 2025 |
| Woden Corporate Finance Limited | Professional & scientific | 2013 |
| Wold Hospitality Group Ltd | Professional & scientific | 2025 |
| Wolf & Vrooman Limited | Administrative & support | 2024 |
| Wolfin Textiles Limited | Wholesale & retail | 1941 |
| Women of a Certain Stage Limited | Professional & scientific | 2007 |
| Wonder Bidco Limited | Financial services | 2021 |
| Wonder Topco Limited | Financial services | 2021 |
| Wood & Stone Construction Limited | Construction | 2005 |
| Woodbridge Solutions Limited | Information & communication | 2007 |
| Woodland Joy Celebrations Ltd | Other services | 2025 |
| Woodspeen Limited | | 1987 |
| Woodward Joinery Ltd | Manufacturing | 2011 |
| World Brands Ltd | Wholesale & retail | 2026 |
| World Illustrated Limited | Information & communication | 2020 |
| World Youth Guitar Festival Ltd | Education | 2018 |
| Wotscold Ltd | Wholesale & retail | 2023 |
| Woww Cleaning Service Ltd | Administrative & support | 2024 |
| WPS United Kingdom Limited | Manufacturing | 2001 |
| Wright Metrology Ltd | Professional & scientific | 2026 |
| Wright Rundle Ltd | Construction | 2003 |
| WVW Ltd | Construction | 2014 |
| X Mark Productions Ltd | Construction | 2008 |
| X Marks the Spot Designs Limited | Professional & scientific | 2023 |
| XA Underwriting Solutions Limited | Financial services | 2023 |
| XB Benelux Ltd | Administrative & support | 2010 |
| XB Luxembourg Ltd | Administrative & support | 2026 |
| XBS Consultancy Ltd | Information & communication | 2025 |
| Xiii Media Limited | Professional & scientific | 2019 |
| Xylem Dewatering Solutions UK Ltd | Manufacturing | 1931 |
| Y Sport Limited | Professional & scientific | 2015 |
| Yakshy Enterprise Ltd | Information & communication | 2022 |
| Yalh Limited | Wholesale & retail | 2014 |
| Yeevee Limited | Information & communication | 2021 |
| Yellow Depot Ltd | Wholesale & retail | 2011 |
| Yellow Lorry Ltd | Wholesale & retail | 2009 |
| YEW Cottage Ltd | Hospitality | 2015 |
| Yhass Home Ltd | Real estate | 2025 |
| Yiangou Architects Limited | Professional & scientific | 2014 |
| Yogni Limited | Wholesale & retail | 2024 |
| Yokora Limited | Wholesale & retail | 2022 |
| YOU Consulting Limited | Professional & scientific | 2021 |
| YOU Want WE Have Ltd | Information & communication | 2013 |
| Your Best Next Move Limited | Education | 2002 |
| Your Community Ltd | Arts & recreation | 2010 |
| Zaini Lifestyle Ltd | Wholesale & retail | 2023 |
| Zaparka Limited | Information & communication | 2012 |
| ZED 23 Ltd | Construction | 2019 |
| Zeroavia Ltd | Manufacturing | 2018 |
| Zerodrytime (Bath) Ltd | Administrative & support | 2017 |
| ZIC ZAC Ltd | Other services | 2025 |
| Zinc Decor Limited | Manufacturing | 2015 |
| Zipwire Limited | Professional & scientific | 2015 |
| Zjaz Ltd | Households | 2024 |
| Zoom PA Limited | Administrative & support | 2020 |
| Zota Limited | Construction | 1997 |
| Zycko Group Limited | Financial services | 2013 |
| Zycko Overseas Limited | Professional & scientific | 2001 |