| Wilderness Fine Art Photography Ltd | Professional & scientific | 2023 |
| Wilderness Tech Ltd | Construction | 2025 |
| Wildlux Solutions LLP | | 2015 |
| Wildring Ltd | Professional & scientific | 2024 |
| Wilkins Business LLP | | 2013 |
| Wilkynet.Uk Limited | Extraterritorial | 2024 |
| Williamsgood Ltd | Financial services | 2025 |
| Willow & Whistles Holidays Ltd | Hospitality | 2025 |
| Willow's Pet Supplies Ltd | Wholesale & retail | 2021 |
| Willows Housing Ltd | Construction | 2022 |
| Willowsland Ltd | Agriculture & fishing | 2024 |
| Wilpat Multiserve Ltd | Transport & logistics | 2023 |
| Wilson IP Limited | Professional & scientific | 2013 |
| Wimbledon Therapy Limited | Health & social care | 2015 |
| WIN That Car Ltd | Administrative & support | 2025 |
| Wincredible Competitions Ltd | Arts & recreation | 2025 |
| Windlane Commerce L.P. | | 2017 |
| Windvale Trading Limited | Wholesale & retail | 2013 |
| Winestorrs Ltd | Wholesale & retail | 2023 |
| Wing AGI Ltd | Information & communication | 2025 |
| Wingspar Ltd | Information & communication | 2023 |
| Winmax Industrial Limited | Extraterritorial | 2015 |
| Winnow Property Ltd | Real estate | 2024 |
| Winox Motorworks Limited | Wholesale & retail | 2025 |
| Winterbourne Property Investments Ltd | Real estate | 2025 |
| Wirejinn Limited | Wholesale & retail | 2023 |
| Wirral Plastics Ltd | Wholesale & retail | 2026 |
| Wisebit Tech Consultancy Ltd | Information & communication | 2025 |
| Wisemark Experts LP | | 2019 |
| Wisetravel Technology Limited | Administrative & support | 2026 |
| With Wisdom Ltd | Administrative & support | 2017 |
| Withalight Ltd | Education | 2025 |
| Withinu Sport & Wellbeing CIC | Health & social care | 2025 |
| Without Banners Ltd | Professional & scientific | 2025 |
| Wiwo Noodle Bar Ltd | Information & communication | 2022 |
| WJM International (UK) Ltd | Mining & quarrying | 2012 |
| Wobz Ltd | Wholesale & retail | 2026 |
| Wolf Horizon Ltd | Wholesale & retail | 2025 |
| Wolfmark Ltd | Information & communication | 2026 |
| Women in Neuroscience UK Ltd | Wholesale & retail | 2024 |
| Women of Virtue Prayer Meeting Ltd | Professional & scientific | 2024 |
| Women's Declaration International Ltd | Other services | 2019 |
| Wonder Apps Limited | Information & communication | 2026 |
| Wonderfarm Limited | Wholesale & retail | 2012 |
| Wonderful-Ness Ltd | Information & communication | 2024 |
| Wonderland Media Ltd | Professional & scientific | 2024 |
| Wood Ceylon Ltd | Manufacturing | 2023 |
| Wood Fellers Ltd | Agriculture & fishing | 2021 |
| Woodpark Industries Ltd | Wholesale & retail | 2009 |
| Woolly WOL Limited | Education | 2026 |
| Woonwear Ltd | Wholesale & retail | 2020 |
| Word of Mouth Technologies Ltd | Information & communication | 2022 |
| Wordphrase Ltd | Other services | 2017 |
| Work IT Through CIC | Education | 2022 |
| Work Trained Limited | Education | 2023 |
| Worker BEE Financial Services Limited | Professional & scientific | 2025 |
| Workgate Global Ltd | Information & communication | 2019 |
| Workman Green Life Landscaping Ltd | Construction | 2025 |
| World Fitness Fraternity Group Limited | Wholesale & retail | 2025 |
| World Frame Ltd | Wholesale & retail | 2025 |
| World International News Ltd | Information & communication | 2025 |
| World of Treatz Ltd | Manufacturing | 2025 |
| World Sports Entertainment Limited | Extraterritorial | 2008 |
| Worlds Racing Ltd | Manufacturing | 2024 |
| Worldwide Chain Stores Limited | Information & communication | 2000 |
| Wornwithgrace Ltd | Wholesale & retail | 2026 |
| Worthy GAL Ltd | Wholesale & retail | 2019 |
| Wraith Enterprises Ltd | Wholesale & retail | 2026 |
| Wreck Tangle Games Ltd | Information & communication | 2016 |
| Wren Canine Hydrotherapy & Rehabilitation Centre Ltd | Professional & scientific | 2020 |
| Wright Reach Digital Ltd | Professional & scientific | 2024 |
| Wrightstuff Media Ltd | Information & communication | 2026 |
| WT Labz Holding Limited | Wholesale & retail | 2018 |
| Wuffly Limited | Wholesale & retail | 2025 |
| Wukongda Global Limited | Wholesale & retail | 2021 |
| Wunderstock Limited | Wholesale & retail | 2026 |
| Wynforge Ltd | Information & communication | 2025 |
| Wysecore Group Ltd | Information & communication | 2025 |
| WZ Properties Limited | Real estate | 2024 |
| X Real Estate Ltd | Real estate | 2017 |
| X SCT Ltd | Wholesale & retail | 2024 |
| X-Port Limited | Professional & scientific | 2002 |
| X9RR Limited | Information & communication | 2026 |
| Xact+ Accountants Ltd | Professional & scientific | 2022 |
| Xania Holdings Ltd | Professional & scientific | 2024 |
| Xavari Solutions Ltd | Professional & scientific | 2025 |
| XCH London Limited | Information & communication | 2023 |
| Xcix Ltd | Information & communication | 2019 |
| Xcloud Labs Ltd | Information & communication | 2024 |
| Xcon Events Ltd | Administrative & support | 2026 |
| XEC7 Group Ltd | Professional & scientific | 2020 |
| Xeneo Ltd | Wholesale & retail | 2024 |
| Xenia Plus Ltd | Real estate | 2021 |
| Xenith Property Ltd | Real estate | 2023 |
| Xerixy Ltd | Wholesale & retail | 2025 |
| Xetical Ltd | Extraterritorial | 2020 |
| Xevri Ltd | Wholesale & retail | 2020 |
| XFD Solutions Limited | Professional & scientific | 2024 |
| Xiepro Limited | Wholesale & retail | 2026 |
| Xiguanchen Ltd | Wholesale & retail | 2025 |