| Work Supply Store Ltd | Wholesale & retail | 2026 |
| World of Leisure Limited | Wholesale & retail | 2001 |
| Worlds Energy Ltd | Construction | 2016 |
| Wrenchkraft Limited | Wholesale & retail | 2019 |
| Wrestleforce Ltd | Arts & recreation | 2025 |
| WRH Refurbishments Limited | Construction | 2026 |
| Wright TM Group Limited | Financial services | 2023 |
| Writtle Farm Machinery Ltd | Wholesale & retail | 2012 |
| Wroxham Enterprises Limited | Manufacturing | 1996 |
| Wroxham Marine Limited | Other services | 1995 |
| Wsora Limited | Households | 2001 |
| WSP Victory Inn Limited | Hospitality | 2025 |
| WT Agency Ltd | Administrative & support | 2013 |
| Www.Company-Car-Buyers.Co.Uk Limited | Wholesale & retail | 2016 |
| Xantos Limited | Administrative & support | 2017 |
| Xquisite Detailing Ltd | Wholesale & retail | 2021 |
| XS Aerospares Ltd | Transport & logistics | 2023 |
| XS Aviation Limited | Transport & logistics | 2012 |
| XS Secure Ltd | Administrative & support | 2014 |
| XSP Resources Ltd | Information & communication | 2024 |
| Xtracta Limited | Construction | 2007 |
| Xtreme Studios Limited | Real estate | 2002 |
| Yannickco Limited | Other services | 2015 |
| Yardstick Strategies Limited | Information & communication | 2011 |
| Yasree Works and Trades Limited | Manufacturing | 2024 |
| YEW Freight Trading Limited | Transport & logistics | 2016 |
| Yewdale Corporation Ltd | Manufacturing | 2010 |
| Yewdale Investments Ltd | Financial services | 2014 |
| Yewtree Technical Wickford Limited | Professional & scientific | 2013 |
| Yigitmirac Ltd | Hospitality | 2024 |
| YM Talent Group Limited | Administrative & support | 2026 |
| Yoda Cleaning Ltd | Administrative & support | 2021 |
| Yorkshire Endoscopy Ltd | Health & social care | 2017 |
| Younas&Co Limited | Manufacturing | 2025 |
| Your Battery Expert Ltd | Professional & scientific | 2025 |
| Your Home Property Management Ltd | Households | 2011 |
| Your Time to Shine Limited | Arts & recreation | 2025 |
| Yulefern Ltd | Administrative & support | 2005 |
| YVO Ltd | Professional & scientific | 2010 |
| Zamarhub Ltd | Information & communication | 2026 |
| Zaynco Ltd | Wholesale & retail | 2025 |
| ZB3 Holdings Ltd | Financial services | 2020 |
| ZB3 Technologies Ltd | Manufacturing | 2017 |
| ZCS 125 Limited | Hospitality | 2024 |
| Zenith Advice Ltd | Financial services | 2021 |
| Zenith Astronomy Ltd | Administrative & support | 2024 |
| Zenith Urban Property Ventures Ltd | Real estate | 2026 |
| Zeushaul Ltd | Transport & logistics | 2015 |
| Zeushaul Properties Ltd | Real estate | 2026 |
| ZFG Logistics Ltd | Transport & logistics | 2020 |
| Ziash-Juden Ventures Ltd | Other services | 2014 |
| Zolex Limited | Manufacturing | 2026 |
| Zone Pass Ltd | Transport & logistics | 2016 |
| Zoom! Display Limited | Administrative & support | 2001 |