| Western WAX Artist Limited | Other services | 2024 |
| Westingford Limited | Other services | 2019 |
| Westminster Cleaning Specialists Ltd | Administrative & support | 2022 |
| Wexwood Builders Limited | Financial services | 2001 |
| WG1 Camden Limited | Real estate | 2024 |
| WG1 Offices Ltd | Real estate | 2020 |
| WGO Solutions Ltd | Information & communication | 2011 |
| What Travel Ltd | Administrative & support | 2025 |
| Wheatmare Limited | Professional & scientific | 2014 |
| Whippy Brothers Ltd | Wholesale & retail | 2025 |
| Whisky Circle Ltd | Wholesale & retail | 2023 |
| Whispered Notes Limited | Wholesale & retail | 2026 |
| Whitchurch Business Solutions Limited | Professional & scientific | 2022 |
| Whitchurch Consulting Limited | Information & communication | 2025 |
| Whitchurch Gardens Management Company Limited | Real estate | 2003 |
| Whitchurch Investments Limited | Real estate | 2011 |
| Whitchurch Lane Tyers Ltd | Wholesale & retail | 2013 |
| Whitchurch Lane Tyres & Services Ltd | Wholesale & retail | 2022 |
| Whitchurch Property Investments Limited | Real estate | 2018 |
| White SKI Ltd | Wholesale & retail | 2021 |
| White Sparkling Deep Cleaning Ltd | Administrative & support | 2025 |
| White Thread Tailoring Ltd | Other services | 2023 |
| Whitebox Investments Limited | Real estate | 2017 |
| Whitecraig Developments Limited | Extraterritorial | 1965 |
| Whitecross Street North Limited | Real estate | 2015 |
| Whitemount Projects Limited | Construction | 2018 |
| Whizkid Wonderland Holiday Camp CIC | Education | 2024 |
| WHM Trades Ltd | Wholesale & retail | 2025 |
| WHS Estates Ltd | Real estate | 2026 |
| Wieclaw Consultancy Ltd | Professional & scientific | 2014 |
| Wigwam Livco Limited | Construction | 2019 |
| WIJ Services Limited | Hospitality | 2009 |
| Wild Technologies AI Limited | Information & communication | 2017 |
| Wildernesse Close Limited | Households | 2025 |
| Wilderton Building Consultancy Ltd | Construction | 2015 |
| Wilfred Consultants Limited | Construction | 2012 |
| Wilks Services Limited | Real estate | 2007 |
| Will Writers London Ltd | Other services | 2024 |
| Willgoss P&L Services Limited | Professional & scientific | 2025 |
| Williams Development Capital Limited | Financial services | 2022 |
| Williams Developments (5) Limited | Construction | 2022 |
| Williams Developments (SR) Limited | Construction | 2021 |
| Willmott & John Limited | Construction | 2019 |
| Willsons Ltd | Other services | 2015 |
| Wilnero Ltd | Wholesale & retail | 2025 |
| Wilson Subsea Solutions Ltd | Professional & scientific | 2014 |
| Wimbleridge Limited | Professional & scientific | 2016 |
| Wimpole Street Medical Centre Limited | Real estate | 1981 |
| Windee Marsh Services Ltd | Health & social care | 2023 |
| Windows by Choice Ltd | Construction | 2002 |
| Winel - Energy & Infrastructure Limited | Professional & scientific | 2022 |
| Wing Estates Limited | Real estate | 2007 |
| Wing HO London Ltd | Hospitality | 2017 |
| Winning Accountancy & Consultancy Limited | Professional & scientific | 1983 |
| Winslow Properties Ltd | Real estate | 2022 |
| Winstone Jewels Limited | Wholesale & retail | 2026 |
| Winthrop Gunther Group Holdings Ltd | Real estate | 2026 |
| Winthrop Gunther Group Ltd | Real estate | 2020 |
| Wire Consultant Limited | Professional & scientific | 2022 |
| Wire TEK Limited | Energy | 2021 |
| Wisbech Hotels Ltd | Real estate | 2022 |
| Wise Windows Ltd | Wholesale & retail | 2013 |
| Wiseman & Ashley Limited | Wholesale & retail | 1981 |
| Wiseman Properties Limited | Real estate | 2016 |
| Wishbones Rotisserie PLC | Hospitality | 1995 |
| Wispington House Limited | Health & social care | 2005 |
| Wispville Group Limited | Financial services | 2025 |
| Wispville Investments Limited | Financial services | 2025 |
| Witley Properties Limited | Real estate | 2025 |
| Wittgenstein's Poker Limited | Information & communication | 2021 |
| WMS Global Ltd | Real estate | 2017 |
| Woburn Fish and Chips Limited | Hospitality | 2024 |
| Wolf Grips Ltd | Information & communication | 2022 |
| Wolmer Developments Ltd | Construction | 2018 |
| Wolseycare Limited | Health & social care | 2010 |
| Wong Jowo Limited | Information & communication | 2013 |
| Wong Property Investments Limited | Real estate | 2018 |
| Wood Architecture & Design Ltd | Professional & scientific | 2020 |
| Wood IF I Could Ltd | Manufacturing | 2013 |
| Woodall Refrigeration Limited | Wholesale & retail | 1967 |
| Woodberry Consulting Limited | Administrative & support | 2019 |
| Woodcote (Purley) Limited | Real estate | 2024 |
| Woodhouse Property Consultants Limited | Real estate | 1996 |
| Woodrow Medical Limited | Health & social care | 2023 |
| Woodstone Investment Limited | Real estate | 2018 |
| Woodville Limited | Construction | 2006 |
| Woody Export Limited | Wholesale & retail | 2016 |
| Wooffings Ltd | Wholesale & retail | 2025 |
| Woolwich Kebab & Fried Chicken Ltd | Hospitality | 2013 |
| Wordsworth Court Residents Association (Hatfield) Limited | Real estate | 1980 |
| Worgate Limited | Administrative & support | 2018 |
| Workearly Ltd | Information & communication | 2019 |
| Workplacemedicine Limited | Health & social care | 2022 |
| World Colours Ltd | Manufacturing | 2023 |
| World Congress of Overseas Pakistanis | Health & social care | 2013 |
| World Harvest Ltd | Wholesale & retail | 2025 |
| World of Accessories & Vape Ltd | Wholesale & retail | 2024 |
| Worldbridge Consulting Ltd | Mining & quarrying | 2024 |
| Worldrags Limited | Professional & scientific | 2002 |
| Worldsim Limited | Information & communication | 2006 |