| Wickets Grove Ltd | Wholesale & retail | 2025 |
| Wigton Crest Ltd | Wholesale & retail | 2025 |
| Wilks Lowry Ltd | Wholesale & retail | 2025 |
| Willclaire Palms Ltd | Wholesale & retail | 2025 |
| Willclare Paddock Ltd | Wholesale & retail | 2025 |
| William Bonds Ltd | Wholesale & retail | 2025 |
| William Landscapes & Tree Services Ltd | Administrative & support | 2026 |
| Willow Potters Ltd | Wholesale & retail | 2025 |
| Willson & Wilding Ltd | Wholesale & retail | 1977 |
| Wilmot Property Lettings Limited | Real estate | 2023 |
| Wilowie Ltd | Administrative & support | 2016 |
| Wiltan Holdings Limited | Professional & scientific | 2010 |
| Wiltan Limited | Manufacturing | 1985 |
| Wiltan Power Systems Limited | Professional & scientific | 2026 |
| Wind Catering Limited | Administrative & support | 2016 |
| Window-Rite Limited | Wholesale & retail | 2012 |
| Winrush Casts Ltd | Wholesale & retail | 2025 |
| Winter Stafford Ltd | Wholesale & retail | 2025 |
| Winton Fronts Ltd | Wholesale & retail | 2025 |
| Wired Smart Ltd | Construction | 2023 |
| WJW Investments Ltd | Professional & scientific | 2010 |
| WJW Self Storage (Newport) Ltd | Professional & scientific | 2010 |
| WMJ Decorating Services Ltd | Construction | 2015 |
| WN Contractors Ltd | Construction | 2026 |
| Wodehouse Silver Ltd | Wholesale & retail | 2025 |
| Wonder WAX CYF | Wholesale & retail | 2025 |
| Woodbine Meadow Management Company Limited | Households | 2022 |
| Woodhouse Walters Ltd | Wholesale & retail | 2025 |
| Woodlands Field Limited | Other services | 2008 |
| Workday Bows Ltd | Wholesale & retail | 2024 |
| Workhorse Strength and Conditioning Ltd | Education | 2026 |
| Wqgroup Limited | Extraterritorial | 2025 |
| WW Biomass Services Ltd | Construction | 2019 |
| WW Contracting Ltd | Construction | 2018 |
| WW Energy Services Group Limited | Construction | 2024 |
| WW Fire Sprinklers Ltd | Construction | 2024 |
| WW Heating Services Limited | Construction | 2021 |
| WW Plumbing and Heating Ltd | Construction | 2021 |
| WYE Communications Ltd | Information & communication | 2022 |
| X4W Group Limited | Financial services | 2022 |
| Xav-Eight Ltd | Other services | 2020 |
| Y Prentis | Education | 2012 |
| Yasimi Food and Wine Limited | Wholesale & retail | 2016 |
| Ynys Afallon Property Services Ltd | Real estate | 2020 |
| Yoga for Health Community Interest Company | Health & social care | 2023 |
| York Mayes Ltd | Wholesale & retail | 2025 |
| Your Move Services Ltd | Transport & logistics | 2020 |
| Yrrap Properties Ltd | Real estate | 2025 |
| ZAP and TAP Ltd | Construction | 2026 |
| ZB Kitchen & Bathroom Ltd | Construction | 2024 |
| Zero Plant Hire Limited | Administrative & support | 2020 |
| ZFG Solutions Ltd | Construction | 2015 |
| ZNZ Properties Limited | Real estate | 2022 |