| Workey Limited | Wholesale & retail | 2017 |
| Workforce Employment Solutions Podiatry Limited | Health & social care | 2026 |
| Working Title Limited | Hospitality | 2006 |
| Workpoint Holdings Ltd. | Professional & scientific | 2007 |
| World of Stones UK Holdings Ltd. | Manufacturing | 2018 |
| World Radio Gardening Limited | Information & communication | 2018 |
| World Sake Imports UK Ltd | Wholesale & retail | 2008 |
| World Tour Store Limited | Administrative & support | 2018 |
| World WAR Wrestling Ltd | Arts & recreation | 2014 |
| Worldbridge Limited | Manufacturing | 1987 |
| Wormingford Hall Estate Limited | Agriculture & fishing | 1977 |
| Worton IT Limited | Information & communication | 2022 |
| Worx Construction Ltd | Construction | 2020 |
| Wossner UK Ltd | Manufacturing | 2019 |
| Wppg (Commercial) Limited | Real estate | 2019 |
| Wppg (Residential) Limited | Real estate | 2019 |
| Wppg Holdings Limited | Financial services | 2022 |
| Wreford Court Limited | Households | 2011 |
| Wright Hearing Group Limited | Financial services | 2022 |
| Wright Management Ltd | Construction | 2018 |
| Wright MED Services Ltd | Health & social care | 2019 |
| Wright Ruffell (Residential) Limited | Real estate | 2019 |
| Wright Ruffell (Sturricks) Limited | Construction | 1965 |
| Wright Ruffell Limited | Real estate | 1967 |
| Wright Ruffell Management Limited | Financial services | 2012 |
| Wright Skips Environmental Limited | Water & waste | 2021 |
| Wright Surveys Ltd | Construction | 2022 |
| Wright Top Soil Limited | Administrative & support | 2020 |
| Wright Turf Limited | Administrative & support | 2020 |
| Wrighttmtm Ltd | Construction | 2025 |
| Wrightvanremovals Ltd | Water & waste | 2025 |
| WRM Roth Ltd | Administrative & support | 2021 |
| Wrong Fuel Recovers Ltd | Wholesale & retail | 2025 |
| Wrox & Croft Homes Ltd | Real estate | 2022 |
| WRS Fornham Financial Partners Ltd | Professional & scientific | 2019 |
| WSM Consultancy Ltd | Professional & scientific | 2020 |
| WSS Holdings Limited | Financial services | 1990 |
| WSS Procurement Limited | Wholesale & retail | 1994 |
| WSV Ltd | Professional & scientific | 2025 |
| WSW Lights,Visions & Sounds Ltd | Construction | 2024 |
| Wuffles and Whiskers Ltd | Households | 2022 |
| Wunderlich Terson Ltd | Real estate | 2019 |
| WW Analysis Limited | Professional & scientific | 2022 |
| WW Home Improvement Limited | Construction | 2008 |
| WWG Limited | Other services | 2025 |
| Www.Bad-Bears.Com Ltd | Wholesale & retail | 2025 |
| Www.Chargenet.Online Ltd | Information & communication | 2022 |
| WY BEV Support Ltd | Hospitality | 2025 |
| WY RM Support Ltd | Hospitality | 2025 |
| Wyatt Residentials Ltd | Real estate | 2026 |
| Wykes Holdings Ltd | Financial services | 2022 |
| Wyndeham Icon Limited | Extraterritorial | 1994 |
| Wyndeham Limited | Extraterritorial | 2014 |
| Wynne-Williams Associates Limited | Professional & scientific | 2004 |
| Wyvern Internal Audit Services Limited | Professional & scientific | 2025 |
| Wyvern Planning Limited | Professional & scientific | 2026 |
| Wyvern Projects Ltd | Professional & scientific | 2023 |
| Wyvernwood Limited | Arts & recreation | 2021 |
| X 11 EOD Limited | Professional & scientific | 2010 |
| X Build Group Limited | Construction | 2023 |
| X Trillion Ltd | Information & communication | 2019 |
| X-Car 1 Ltd | Wholesale & retail | 2013 |
| X.E. Website Solutions Ltd | Professional & scientific | 2000 |
| XAT Solutions Ltd | Other services | 2014 |
| Xcell IT Limited | Information & communication | 2015 |
| XD Roofing Limited | Construction | 2021 |
| Xenserv Ltd | Other services | 2020 |
| Xericweb Drying Systems Limited | Manufacturing | 2003 |
| Xerus Care Ltd | Health & social care | 2021 |
| XFX Trading Limited | Financial services | 2002 |
| Xinapse Systems Limited | Information & communication | 2001 |
| Xinyangfeng Akang (Shandong) Fertilizer Import&Export Co., Ltd | Wholesale & retail | 2025 |
| Xodius Limited | Real estate | 2019 |
| Xplicit Logistics Ltd | Wholesale & retail | 2024 |
| Xpress Energy Ltd | Wholesale & retail | 2025 |
| Xpress Fuels Ltd | Wholesale & retail | 2025 |
| Xray Management Support Services Limited | Administrative & support | 2015 |
| Xtalk Project Limited | Education | 2010 |
| Y&Sy Limited | Extraterritorial | 2018 |
| Y-Not Touring Services Ltd | Transport & logistics | 2015 |
| Y1 Services Limited | Real estate | 2025 |
| Yakutay Care Ltd. | Health & social care | 2019 |
| Yallop Ltd | Other services | 2022 |
| Yan&Alexa Voyage Limited | Transport & logistics | 2019 |
| Yanarc Limited | Professional & scientific | 2018 |
| Yanarc UK Elite Ltd | Administrative & support | 2018 |
| Yankono Ltd | Health & social care | 2019 |
| Yarra Services Limited | Health & social care | 2017 |
| Yash Ventures Limited | Administrative & support | 2010 |
| Yashfee Properties Ltd | Real estate | 2024 |
| Yashofflicense Ltd | Wholesale & retail | 2026 |
| Yasin Care Services Ltd | Health & social care | 2013 |
| Yasmeen Hussain Limited | Extraterritorial | 2010 |
| Yatmaz Ltd | Construction | 2020 |
| Yaura Management Agency Ltd | Professional & scientific | 2021 |
| Yawee Estates Hub Ltd | Real estate | 2025 |
| Yawee Foods Ltd | Wholesale & retail | 2014 |
| Yaya's House Limited | Hospitality | 2023 |
| Yazdan Express Group Ltd | Wholesale & retail | 2025 |
| Yazeka Limited | Real estate | 2017 |