| WCR Partners Limited | Financial services | 2020 |
| Weald Business Properties Limited | Real estate | 2025 |
| Weald Park Property Company Limited | Real estate | 2000 |
| Wealth Retention Limited | Water & waste | 2008 |
| Weber Hydraulik (UK) Limited | Extraterritorial | 2003 |
| Weber Rescue UK Limited | Public administration | 2006 |
| Weber UK Limited | Wholesale & retail | 1973 |
| Wellfit Creative Solutions Ltd | Arts & recreation | 2017 |
| Wellness Care Group Ltd | Health & social care | 2024 |
| Wellworthhaving Limited | Extraterritorial | 2010 |
| Wessex Transport Service Ltd | Transport & logistics | 2014 |
| West Street Vineyard LLP | | 2013 |
| Westgate Accounting Limited | Professional & scientific | 2014 |
| Westross Plumbing and Heating Engineers Limited | Construction | 2008 |
| Westross Services (UK) Limited | Extraterritorial | 2011 |
| Westway Ltd | Construction | 2025 |
| Westway Renovations Ltd | Construction | 2025 |
| Weztech Industries Ltd | Wholesale & retail | 2009 |
| Wheel Boss Ltd | Wholesale & retail | 2012 |
| Wheelworx Ipswich Limited | Extraterritorial | 2018 |
| Wheelworx Limited | Administrative & support | 2005 |
| Whirlpool LLP | | 2025 |
| White Hart Halstead Limited | Manufacturing | 2012 |
| White Rabbit Healthcare Ltd | Professional & scientific | 2019 |
| Whitecoatexpress Limited | Construction | 2022 |
| Whitehall Electrical Ltd. | Construction | 2003 |
| Whitehouse Business Solutions Limited | Transport & logistics | 2015 |
| Whitehouse Fulfilment Limited | Wholesale & retail | 2019 |
| Whitehouse Holdings (Halstead) Limited | Professional & scientific | 1996 |
| Whitehouse Spice Processors Limited | Transport & logistics | 1967 |
| Wibsey Fireplace Centre Limited | Wholesale & retail | 2006 |
| Wicks Construction Limited | Real estate | 1983 |
| Wideawake Projects Ltd | Professional & scientific | 2024 |
| Wild Boar Estates Limited | Real estate | 2001 |
| Wild Boar Properties Limited | Construction | 2010 |
| William Austin Holdings Limited | Construction | 2024 |
| William Austin Upholstery Limited | Other services | 2012 |
| Williams & Johnson Decorating Services Limited | Construction | 2015 |
| Williams Applied Sciences Services Ltd. | Construction | 2014 |
| Willow Tree Consulting Ltd | Professional & scientific | 2021 |
| Wilsdon Little Limited | Hospitality | 2019 |
| Wilson Environmental Ltd | Water & waste | 2014 |
| Window Decor Solutions Ltd | Manufacturing | 2021 |
| Wingspan Designs Ltd | Extraterritorial | 2009 |
| Wisteria Investments Limited | Construction | 2026 |
| Witham Plumbing & Heating Ltd | Construction | 2019 |
| Wivenhoe Builders Ltd | Construction | 2020 |
| Wivenhoe Repair Reuse Recycle CIC | Health & social care | 2016 |
| WJH Grab Hire Limited | Transport & logistics | 2017 |
| Wonder Nurseries Ltd | Education | 2024 |
| Wonderful Health Care Ltd | Health & social care | 2023 |
| Woodcivils Ltd | Construction | 2010 |
| Woodertons Farm Livery Limited | Agriculture & fishing | 2025 |
| Woodham Court RTM Company Limited | Real estate | 2006 |
| Wrightseal Limited | Construction | 2015 |
| WSA Limited | Professional & scientific | 2021 |
| WSP Accountancy Limited | Professional & scientific | 2020 |
| WTE Homes Ltd | Real estate | 2019 |
| Wyvern Trading Ltd | Construction | 2007 |
| Xcel Ventures Limited | Real estate | 2011 |
| Xena Automotive Management Ltd | Wholesale & retail | 2013 |
| Xenace Ltd | Information & communication | 2015 |
| Xvir Limited | Real estate | 2016 |
| Yellow House Alternative Education Limited | Education | 2002 |
| Yezi Ltd | Transport & logistics | 2014 |
| Yokon Films Ltd | Information & communication | 1997 |
| Yokon Ltd | Other services | 2011 |
| Yokon Media Ltd | Information & communication | 2016 |
| Young Farming Ltd | Agriculture & fishing | 2025 |
| Your Payroll Team Ltd | Administrative & support | 2023 |
| Zeitgeist Motors Limited | Wholesale & retail | 2015 |
| Zensation Limited | Other services | 2024 |
| Zermut Ltd | Hospitality | 2022 |
| Zeya Holdings (Halstead) Limited | Construction | 1980 |