| Watersafe Installers' Scheme Limited | Other services | 2012 |
| Waymar Limited | Financial services | 2012 |
| Wayo GAS Ltd | Construction | 2024 |
| WE ARE Marketing UK Limited | Professional & scientific | 2014 |
| WE Fight ANY Claim Limited | Administrative & support | 2008 |
| WE-R-P38'S Ltd. | Wholesale & retail | 2018 |
| Webberts Ltd | Construction | 2025 |
| West USK Consulting Ltd | Wholesale & retail | 2019 |
| Westaid Training Ltd | Public administration | 2018 |
| Western Finance Limited | Real estate | 2006 |
| WGE Wealth Management Ltd | Professional & scientific | 2026 |
| Wheel Bakery Ltd | Wholesale & retail | 2026 |
| Whitehorn Marketing Limited | Wholesale & retail | 2023 |
| Whitelenz Ltd | Professional & scientific | 2022 |
| Wholesale Motion Limited | Wholesale & retail | 2020 |
| Wibzee Ltd | Wholesale & retail | 2025 |
| Wild Details Ltd | Administrative & support | 2025 |
| Wild Print Ltd | Manufacturing | 2014 |
| Wild Reconnection CIC | Health & social care | 2026 |
| Wildflower Film Ltd | Arts & recreation | 2021 |
| Willcom Ltd | Wholesale & retail | 2016 |
| Wilmot-Breeden (Holdings) Limited | Administrative & support | 1948 |
| Window Canopy Ltd | Manufacturing | 2022 |
| Window Kanopy Ltd | Manufacturing | 2018 |
| Winteroak Homes Limited | Real estate | 2024 |
| Wired Power & Lighting Limited | Construction | 2022 |
| Wjss Properties Limited | Real estate | 2018 |
| WJW Scaffolding Limited | Construction | 2011 |
| WJW Self Storage (Cwmbran) Ltd | Professional & scientific | 2010 |
| WMP Group Ltd | Real estate | 2019 |
| WMP Property Ltd | Real estate | 2019 |
| Wmp-Re Ltd | Wholesale & retail | 2019 |
| Woodrise Access Ltd | Construction | 2020 |
| Woodside Joinery (Staircases) Limited | Manufacturing | 2004 |
| Wootton Group Renewables Ltd | Construction | 2024 |
| Work & Meet Ltd | Administrative & support | 2019 |
| WP Transport Limited | Transport & logistics | 2017 |
| Wren's Nest (South Wales) Limited | Construction | 2021 |
| Wright Computers Limited | Information & communication | 1990 |
| Wuerth Industry Service LLP | | 2019 |
| Wulfgang Dog Training Limited | Other services | 2022 |
| X1 Products Ltd | Wholesale & retail | 2024 |
| XD Replica Ltd | Arts & recreation | 2024 |
| Y Bwyty Ltd | Hospitality | 2024 |
| Y Plant Affricanaidd Community Interest Company | Public administration | 2022 |
| Yamaka Ltd | Professional & scientific | 2026 |
| Yearnhome Improvements Limited | Manufacturing | 2012 |
| YOU GOT to Want IT Ltd | Wholesale & retail | 2022 |
| YOU2PROPERTY Investment Company Limited | Real estate | 2020 |
| Young Persons Secure Transport UK Ltd | Transport & logistics | 2026 |
| Youngs Motor Sales Ltd | Wholesale & retail | 2024 |
| Yukon Foods Ltd | Hospitality | 2024 |
| Yuricher Ltd | Professional & scientific | 2025 |
| Yusra Kitchen Ltd | Hospitality | 2025 |
| Zagalas Limited | Manufacturing | 2025 |
| Zeffa Online Limited | Wholesale & retail | 2011 |
| Zest Tax Limited | Professional & scientific | 2020 |
| Zhannadee Cleaning Ltd | Administrative & support | 2020 |
| Zodiac Creator Network Ltd | Information & communication | 2025 |
| ZOE Trigwell Academy Ltd | Wholesale & retail | 2019 |
| Zoom Freight Limited | Information & communication | 2011 |
| ZPT Consulting Ltd | Professional & scientific | 2025 |
| ZRE Ltd | Real estate | 2024 |
| ZUR Homes Ltd | Real estate | 2024 |
| Zwanny Ltd | Professional & scientific | 2013 |