| WG STH Limited | Arts & recreation | 2011 |
| Whatton Investment Company Limited | Real estate | 2017 |
| Wheater Bickley Limited | Extraterritorial | 2013 |
| Whelpley Hill Park Limited | Hospitality | 1992 |
| Whippersnapper Productions Limited | Arts & recreation | 2003 |
| White Hill House 128 Ltd | Health & social care | 2015 |
| Whitlaw Limited | Professional & scientific | 2016 |
| WHOLESALE4RESALE Ltd | Wholesale & retail | 2022 |
| Wild Goose Labs Limited | Information & communication | 2014 |
| Wild Hearts Therapeutic Adventures Ltd | Other services | 2021 |
| Wild Horse Services Ltd | Other services | 2021 |
| Wild Moose Labs Limited | Other services | 2014 |
| Wilde Wood Films Limited | Information & communication | 2018 |
| Wildebeest Cars Limited | Wholesale & retail | 2023 |
| Wildfish Swim School (Bucks) LLP | | 2023 |
| Wildfish Swim School (South) LLP | | 2025 |
| Wildfish Swim School LLP | | 2021 |
| Willchem Ltd | Financial services | 2022 |
| William Hains Holdings Limited | Professional & scientific | 2018 |
| Williams Properties Surrey Limited | Real estate | 2024 |
| Williams-Schone Ltd | Administrative & support | 2016 |
| Willow Gate House Management Company Limited | Households | 1976 |
| Willspur Group Ltd | Wholesale & retail | 2021 |
| Wilsher Scenic Services Ltd | Manufacturing | 2019 |
| Wilson Heal Limited | Extraterritorial | 2010 |
| Wilson Home & Garden Ltd | Households | 2024 |
| Wilsons Residential Lettings Limited | Real estate | 2001 |
| Wilton Mettler Ltd | Real estate | 2020 |
| Wiltonpost Property Management Limited | Households | 1997 |
| Win-Win Parenting International Limited | Education | 2010 |
| Winara Technology Services Ltd | Administrative & support | 2021 |
| Winchester Technology Group Ltd | Information & communication | 2023 |
| Winco Property Limited | Real estate | 2017 |
| Window Film Solutions (UK) Limited | Manufacturing | 2008 |
| Window Wise Company Limited | Construction | 1981 |
| WINGS2LEARN CIC | Education | 2024 |
| Winzor Pharmaceuticals UK Limited | Manufacturing | 2011 |
| Wisdom Tutors Ltd | Professional & scientific | 2020 |
| Wisegate Limited | Real estate | 1987 |
| WJD Holdings Limited | Real estate | 2025 |
| WOM Growth Ltd | Professional & scientific | 2024 |
| Wonderwall Paint Ltd | Construction | 2024 |
| Woodhall Personnel Recruitment Ltd | Administrative & support | 2019 |
| Woodlands Nursery Ruislip Limited | Education | 2017 |
| Woodley Electrical Services Ltd | Construction | 2016 |
| Workaid | Health & social care | 1991 |
| Workin Progress Limited | Education | 2013 |
| Workout Workdown Ltd | Health & social care | 2024 |
| Wotnot Vintage Cafe Ltd | Hospitality | 2019 |
| Wowfashion Ltd | Wholesale & retail | 2019 |
| Wright's Plumbing & Heating Ltd | Construction | 2020 |
| Wrights Fencing and Landscaping Limited | Administrative & support | 2015 |
| Wyckoff Analytics Limited | Administrative & support | 2015 |
| Wycombe & District Motor Cycle Club Limited | Arts & recreation | 1991 |
| WZ Designs Ltd | Professional & scientific | 2020 |
| X6 CDN Limited | Real estate | 2019 |
| Xero Consultants Limited | Professional & scientific | 2017 |
| Xinnovate UK Ltd | Information & communication | 2019 |
| Xnrg Limited | Arts & recreation | 2017 |
| Xylotech Ltd | Information & communication | 2022 |
| Yasmin Properties Limited | Real estate | 2021 |
| Yatlina Limited | Other services | 2020 |
| Yelmer Ltd | Wholesale & retail | 2017 |
| Yerrell Flooring (Bucks) Ltd | Wholesale & retail | 2020 |
| YIG Bros Property Ltd | Real estate | 2024 |
| YKW International Ltd | Wholesale & retail | 2015 |
| Yoga Mali Ltd | Education | 2024 |
| Yorgova Holdings Ltd | Financial services | 2024 |
| Yorgova Property Investments Limited | Real estate | 2024 |
| Youngbair Ltd | Financial services | 2019 |
| Youngs Whiskers & Paws Ltd | Other services | 2019 |
| Youtubs Ltd | Wholesale & retail | 2020 |
| Yummy Discoveries Ltd. | Professional & scientific | 2012 |
| Yzis Properties Ltd | Real estate | 2024 |
| ZA Plumbing and Heating Ltd | Construction | 2025 |
| Zakatuna Ltd | Information & communication | 2024 |
| Zaki and SAM Ltd | Other services | 2022 |
| Zanaki Limited | Health & social care | 2024 |
| Zelda Digital Consultancy Ltd | Professional & scientific | 2022 |
| Zerafa Industries Ltd | Information & communication | 2023 |
| Zerberzum Limited | Information & communication | 2004 |
| Zero Proof International Limited | Manufacturing | 2018 |
| Zero Proof UK Limited | Manufacturing | 2018 |
| ZF Motors Ltd | Wholesale & retail | 2020 |
| Zhenjiang Star Group Limited | Administrative & support | 2002 |
| ZI Cloud Limited | Information & communication | 2023 |
| ZI Commerce Ltd | Wholesale & retail | 2022 |
| Zicmic Limited | Other services | 2017 |
| Zinc-C Ltd | Information & communication | 2021 |
| Ziptrix Ltd | Information & communication | 2024 |
| ZM (HWB) Ltd | Construction | 2006 |
| ZSK Consulting Limited | Education | 2024 |
| Ztec Laptops Ltd | Information & communication | 2025 |
| ZY Limited | Hospitality | 2026 |