| Watford Jazz Junction CIC | Arts & recreation | 2020 |
| Watford Joinery Limited | Professional & scientific | 1998 |
| Watford M.C. Limited | Other services | 2003 |
| Watford Maeme's Limited | Hospitality | 2020 |
| Watford Marquees Ltd | Administrative & support | 2022 |
| Watford ME Limited | Construction | 2025 |
| Watford Mechanics & Tyres Ltd | Wholesale & retail | 2025 |
| Watford Medical Ltd | Health & social care | 2018 |
| Watford MOT Station Limited | Wholesale & retail | 2019 |
| Watford Motors Ltd | Wholesale & retail | 2018 |
| Watford Naturist Swimming Club | Arts & recreation | 2013 |
| Watford New Hope Trust | Other services | 2000 |
| Watford Pizza & Kebab Ltd | Hospitality | 2025 |
| Watford Plant Hire Ltd | Administrative & support | 2012 |
| Watford Power Services Ltd | Construction | 2025 |
| Watford Property Management (UK) Ltd | Extraterritorial | 2015 |
| Watford Property Sales & Lettings Ltd | Extraterritorial | 2015 |
| Watford Recovery Ltd | Wholesale & retail | 2024 |
| Watford Refrigeration and Air Conditioning Limited | Manufacturing | 1948 |
| Watford Safety & Constructions Services Ltd | Construction | 2025 |
| Watford Scans Limited | Health & social care | 2019 |
| Watford School Uniforms Ltd | Wholesale & retail | 2019 |
| Watford Sheltered Workshop Limited | Administrative & support | 1963 |
| Watford Sweets Ltd | Hospitality | 2015 |
| Watford Symphony Orchestra Productions Limited | Arts & recreation | 2026 |
| Watford Tactical Fighting Ltd | Arts & recreation | 2025 |
| Watford Taxis Ltd | Transport & logistics | 2025 |
| Watford Tiling Ltd | Construction | 2025 |
| Watford Trading Ltd | Wholesale & retail | 2025 |
| Watford Trust Trading Limited | Education | 2008 |
| Watford Tyres & Auto Centre Ltd | Wholesale & retail | 2018 |
| Watford Tyres Limited | Wholesale & retail | 2025 |
| Watford Urban Developments Ltd | Construction | 2026 |
| Watford Windows & Cleaning Services Ltd | Administrative & support | 2025 |
| Watford Women's Centre | Health & social care | 2002 |
| Watforddosa Ltd | Wholesale & retail | 2025 |
| Watfordleather Limited | Wholesale & retail | 2020 |
| Watling Mansions Management Limited | Households | 2000 |
| Watling Street Residents Association Limited | Households | 1971 |
| Wavedash Ltd | Information & communication | 2019 |
| Waverley Garden Limited | Households | 1989 |
| Waverley Road Management Company Limited | Households | 2000 |
| Waves Psychology Ltd | Information & communication | 2024 |
| Waveyllama Ltd | Wholesale & retail | 2020 |
| Wavup Ltd | Wholesale & retail | 2025 |
| Wavy Army Records Ltd | Information & communication | 2025 |
| WAW Studios Ltd | Information & communication | 2024 |
| Wayfin Ltd | Information & communication | 2026 |
| Wayne Fischer Limited | Information & communication | 2019 |
| Waystone (Holdings) Limited | Professional & scientific | 2014 |
| Waystone 32 Limited | Construction | 1995 |
| Waystone Developments Limited | Construction | 2008 |
| Waystone Hargreaves Land LLP | | 2014 |
| Waystone Limited | Construction | 1989 |
| WB Wealth Holdings Limited | Professional & scientific | 2020 |
| WB Wealth Limited | Financial services | 2013 |
| Wcht Devco Limited | Hospitality | 2015 |
| WD Appliance Repairs Ltd | Other services | 2024 |
| WE ARE Acuity Limited | Professional & scientific | 2008 |
| WE ARE Studio Thirteen Ltd | Professional & scientific | 2023 |
| WE ARE Young Limited | Professional & scientific | 2025 |
| WE Buy Best Home Limited | Real estate | 2025 |
| WE Process Ltd | Information & communication | 2020 |
| WE Sell Carpets.Co.Uk Limited | Wholesale & retail | 1998 |
| WE Translate Ltd | Professional & scientific | 2021 |
| Weald Stone Ventures Limited | Manufacturing | 2014 |
| Wealdstone Consulting Ltd | Information & communication | 2022 |
| Wealth Catalyst Consultancy Ltd | Professional & scientific | 2024 |
| Wear-Me! Limited | Manufacturing | 2005 |
| Weaveai Systems Ltd | Information & communication | 2026 |
| Web of Stories Limited | Information & communication | 2003 |
| WEB2PRINT Consulting Limited | Information & communication | 2020 |
| Webb & Webb Ltd | Information & communication | 2021 |
| Webb Labs Ltd | Information & communication | 2025 |
| Weborzo Tech London Limited | Wholesale & retail | 2020 |
| Webpace Limited | Information & communication | 2025 |
| Webprism Limited | Information & communication | 2021 |
| Webtowork Ltd | Professional & scientific | 2015 |
| Weekend Deals Limited | Financial services | 2015 |
| Weekes & Jackson Limited | Real estate | 2025 |
| Wefixit Repair Services Ltd | Other services | 2021 |
| Wefuture Limited | Information & communication | 2015 |
| Weikeong Consultancy Limited | Professional & scientific | 2023 |
| Weirmead Holdings Limited | Financial services | 2026 |
| Welbury Labs Ltd | Professional & scientific | 2024 |
| Welch Media Ltd | Professional & scientific | 2026 |
| Welcome HOM Limited | Real estate | 2025 |
| Welcome House Care Home Services Limited | Health & social care | 2026 |
| Weld Master Dami Ltd | Manufacturing | 2026 |
| Weld Specialists Ltd | Construction | 2025 |
| Weldonstar Properties Limited | Other services | 1999 |
| Well Street INK Limited | Real estate | 2025 |
| Wellair Limited | Energy | 2017 |
| Wellbeing Assured Healthcare Ltd | Administrative & support | 2018 |
| Wellchem Limited | Wholesale & retail | 2021 |
| Wellcrest Trading Limited | Hospitality | 2016 |
| Welldone Assembly Limited | Other services | 2015 |
| Weller Modelmaking Limited | Information & communication | 2015 |
| Wellesley Club UK | Other services | 2015 |
| Wellington Consultancy Ltd | Professional & scientific | 2019 |