| Wall Art Group Ltd | Wholesale & retail | 2026 |
| Wallington Properties Ltd | Real estate | 2020 |
| Walsons Consulting Ltd | Information & communication | 2026 |
| Ward Bailey Properties Limited | Real estate | 2019 |
| Warmur Limited | Construction | 2015 |
| Waterpage Estates Limited | Professional & scientific | 1983 |
| Waterpage Limited | Extraterritorial | 1985 |
| Waterside Retreat Cottage Limited | Hospitality | 2023 |
| Wayward Info Limited | Extraterritorial | 2008 |
| WB Domestic Building Ltd | Construction | 2024 |
| WDS Enterprises Ltd | Administrative & support | 2024 |
| WE ARE Project X Limited | Administrative & support | 2021 |
| WE ARE the Cheek Ltd | Manufacturing | 2023 |
| WE Transform Finance Ltd | Professional & scientific | 2018 |
| Weadon Limited | Real estate | 2008 |
| Webtastic Ltd | Wholesale & retail | 2020 |
| Wecairr Ltd | Administrative & support | 2022 |
| Welchem Europe Ltd | Wholesale & retail | 2017 |
| Welwin Europe Ltd | Wholesale & retail | 2011 |
| Welwin Infotech Ltd | Information & communication | 2018 |
| Wembley Staircase Manufacturer Ltd | Manufacturing | 2014 |
| Wendover Landscapes Ltd | Administrative & support | 2025 |
| Wentworth Computer Holdings Limited | Wholesale & retail | 1987 |
| West END Reward Consulting Ltd | Professional & scientific | 2024 |
| West Way Holidays Limited | Real estate | 2025 |
| Westlake Consulting Limited | Professional & scientific | 2015 |
| Westmount Avenue (Amersham) Management Company Limited | Households | 2002 |
| Weston Healthcare Limited | Health & social care | 2023 |
| Westrow Mushroom Farm Limited | Construction | 1955 |
| WET Bandits PUB Company Ltd | Hospitality | 2024 |
| What YOU SEE and Hear Ltd | Wholesale & retail | 2009 |
| Whellock Consulting Ltd | Professional & scientific | 2016 |
| White Arrow Enterprises Limited | Transport & logistics | 2002 |
| White Gates Ventures Ltd | Real estate | 2025 |
| White Line Consulting Ltd | Professional & scientific | 2013 |
| White Lion Road Management Company Limited | Extraterritorial | 2004 |
| White Properties (UK) Limited | Real estate | 1993 |
| Widening Horizons Limited | Education | 2022 |
| Wigmore 33 Limited | Administrative & support | 2012 |
| Wikani Ltd | Real estate | 2018 |
| Wilderness Properties Limited | Arts & recreation | 1958 |
| Wildfire-Communications Ltd | Professional & scientific | 2021 |
| Wilkes Will Writers Ltd | Financial services | 2008 |
| Will Dent Services Limited | Information & communication | 2013 |
| Willen Shopping Centre LP | | 2014 |
| William Crocker Limited | Financial services | 2016 |
| Williams Plumbing & Heating Ltd | Construction | 2011 |
| Willow Commercial Limited | Professional & scientific | 2025 |
| Willow Garden Services & Maintenance Limited | Administrative & support | 2021 |
| Willox Bikes Limited | Wholesale & retail | 2020 |
| Willox Consulting Limited | Professional & scientific | 2017 |
| Wilson Learning Europa Limited | Education | 1981 |
| Winchley Secretarial Limited | Administrative & support | 2012 |
| Winchmore Mortgages & Protection Ltd | Financial services | 2022 |
| Wine by James Limited | Wholesale & retail | 2024 |
| Wine Logistics Ltd | Professional & scientific | 2020 |
| Wines of China Ltd | Wholesale & retail | 2024 |
| Wing Capital Partners Limited | Information & communication | 2023 |
| Winspit Properties Limited | Construction | 2019 |
| Winters Consulting Ltd | Professional & scientific | 2025 |
| Without Which NOT Ltd | Professional & scientific | 2023 |
| Wizard Travel Limited | Professional & scientific | 2024 |
| WL Newco Ltd | Information & communication | 2024 |
| Wonder Bakery Company Ltd | Wholesale & retail | 2020 |
| Woodcock Films Limited | Information & communication | 2019 |
| Woodley & Hart Kitchens Bedrooms & Bathrooms Ltd | Wholesale & retail | 2019 |
| Woodley & Hart Limited | Wholesale & retail | 2017 |
| Woodside Fish Limited | Hospitality | 2022 |
| Working Media Limited | Information & communication | 1997 |
| Working the Future Ltd | Professional & scientific | 2016 |
| Worx Heating Limited | Construction | 2013 |
| WOW Go Production Limited | Information & communication | 2023 |
| Wsmu Limited | Manufacturing | 2009 |
| Wtjj Limited | Professional & scientific | 2021 |
| Wycombe Medical Acupuncture (WMA) Limited | Health & social care | 2022 |
| Wycombe Roofing Ltd | Construction | 2023 |
| Wyse Solutions Ltd | Manufacturing | 2003 |
| Xclsuive Group Limited | Information & communication | 2020 |
| Xxxified Limited | Manufacturing | 2025 |
| Xyto Taxology Limited | Information & communication | 2015 |
| Y3000 Limited | Information & communication | 2016 |
| Yansh Properties Limited | Real estate | 2020 |
| Yansh Technologies Ltd | Information & communication | 2018 |
| Yanshtech Ltd | Information & communication | 2022 |
| Yari Lifestyle Limited | Wholesale & retail | 2023 |
| Yarli Tech Ltd | Information & communication | 2022 |
| Yelen Ltd | Wholesale & retail | 2026 |
| Yellapu Properties Limited | Real estate | 2022 |
| Yellapu Soft Limited | Information & communication | 2017 |
| Yield Leadership Ltd | Information & communication | 2025 |
| YJP Consulting Ltd | Other services | 2017 |
| Yokoso Limited | Hospitality | 2020 |
| Yorba Consulting Limited | Information & communication | 2022 |
| York Code Limited | Information & communication | 2011 |
| Your Mobile Mechanics Limited | Wholesale & retail | 2018 |
| Your Pivot Pilot Limited | Professional & scientific | 2026 |
| YSB Solutions Ltd | Information & communication | 2024 |
| Zapp Innovation Limited | Information & communication | 2014 |
| Zerotek Group Limited | Construction | 2025 |
| ZF Contracting Services Ltd | Professional & scientific | 2015 |