| Wipelogic Ltd | Wholesale & retail | 2025 |
| Withers and Sons Ltd | Construction | 2014 |
| Wolf Prestige Automotive Ltd | Wholesale & retail | 2019 |
| Womens Business Network Cambridge Ltd | Other services | 2023 |
| Wonderich Construction and Property Maintenance Ltd | Manufacturing | 2025 |
| Wonderlandartwithalice Ltd | Arts & recreation | 2025 |
| WOO Wellness Limited | Health & social care | 2018 |
| Woodbourne (Furniture) Limited | Manufacturing | 2002 |
| Woodgrove Limited | Construction | 2019 |
| Woodland Rangers Ltd | Education | 2023 |
| Woodlands Tree Care Ltd | Administrative & support | 2025 |
| Woodside Builders ( Bishop’S Stortford) Ltd | Construction | 2026 |
| Woodside Delivery Ltd | Information & communication | 2023 |
| Woodview Manor Estates Ltd | Hospitality | 2025 |
| Woodwave Consultancy Ltd | Professional & scientific | 2024 |
| Wooster Landscaping Limited | Administrative & support | 2025 |
| Worktops Bespoke Ltd | Professional & scientific | 2026 |
| Worland Investments Limited | Real estate | 2005 |
| World of People's Promotions Limited | Arts & recreation | 2019 |
| WOW Gifts and Accessories Limited | Wholesale & retail | 2018 |
| Wrctech Ltd | Professional & scientific | 2022 |
| Wreckognition Ltd | Professional & scientific | 2020 |
| Wrenways Limited | Real estate | 2007 |
| Wright Cars Mot's & Service Centre Limited | Wholesale & retail | 2023 |
| Wright Event Supplies Limited | Administrative & support | 2009 |
| WRN Builders Ltd Limited | Construction | 2025 |
| WT Productions Ltd | Extraterritorial | 2022 |
| WWC Double Glazing Ltd | Manufacturing | 2025 |
| Wychford Limited | Administrative & support | 2014 |
| Wylie Flooring Limited | Construction | 2025 |
| X Terrace Fashion Ltd. | Other services | 2014 |
| X-Periment Ltd | Information & communication | 2021 |
| Xcribe Limited | Information & communication | 2023 |
| Xtian Development Ltd | Professional & scientific | 2016 |
| Xupes Handbags & Jewellery Ltd | Wholesale & retail | 2009 |
| Y6 Property Ltd | Real estate | 2019 |
| YA Ticaret Ltd | Hospitality | 2025 |
| Yarlington Investments Ltd | Construction | 2023 |
| Yasrib Solutions Ltd | Other services | 2013 |
| Yelland Architecture Ltd | Professional & scientific | 2015 |
| Yellow Clouds Ltd | Manufacturing | 2021 |
| Yellow Trumpet Limited | Wholesale & retail | 2024 |
| Yenom XOB Limited | Transport & logistics | 2026 |
| Yiayias Corp Limited | Hospitality | 2023 |
| Yiayias Kitchen Winchester Ltd | Wholesale & retail | 2023 |
| Yildirim Cleaning Limited | Administrative & support | 2016 |
| Yotei Capital Ltd | Information & communication | 2025 |
| Young Professionals Guild Ltd | Other services | 2024 |
| Your Property Financial Ltd | Financial services | 2020 |
| Youth Create | Arts & recreation | 1994 |
| Z Weather Ltd | Information & communication | 2019 |
| Zainab Smile Associates Limited | Health & social care | 2016 |
| Zajda-Trans Ltd | Extraterritorial | 2017 |
| Zalisa Limited | Hospitality | 2024 |
| Zanos Ltd | Administrative & support | 2000 |
| Zara KA Ltd | Hospitality | 2024 |
| Zatarin Ltd | Other services | 2012 |
| ZB Solutions Ltd | Administrative & support | 2020 |
| Zenevents Limited | Administrative & support | 2025 |
| Zeray Ltd | Hospitality | 2025 |
| Zerji Properties Ltd | Real estate | 2025 |
| Zinifoods Limited | Hospitality | 2020 |
| ZLD Finance Ltd | Professional & scientific | 2021 |
| Zone H&S Ltd | Real estate | 2024 |
| Zozimus Active Limited | Manufacturing | 2019 |
| Zulu Papa Productions Ltd | Information & communication | 2026 |
| Zuowei Ltd | Real estate | 2022 |
| Zurg Energy Ltd | Construction | 2025 |
| Ôsalé Plage Ltd | Wholesale & retail | 2021 |