| Deborah Beads Limited | Wholesale & retail | 2011 |
| Decades Reloaded Ltd | Arts & recreation | 2020 |
| Decal Links Ltd | Professional & scientific | 2025 |
| Deco Contractors Ltd | Construction | 2013 |
| Decor Pro Ltd | Construction | 2026 |
| Decor Style Limited | Information & communication | 1999 |
| Decorative Events Limited | Other services | 2017 |
| Decoy Solar Farm 3 Limited | Energy | 2024 |
| Dedale Limited | Administrative & support | 2002 |
| Dedav Hair&Beauty Ltd | Other services | 2026 |
| Dedham Angling Club Ltd | Arts & recreation | 2024 |
| Dedham Hall Management Limited | Extraterritorial | 2007 |
| Dedham Investment Ltd | Professional & scientific | 2017 |
| Dedham Landscapes Limited | Other services | 2009 |
| Dedham Mill Management Company Limited | Households | 1986 |
| Dedham Osteopathy Limited | Other services | 2014 |
| Dedham Therapy Farm CIC | Health & social care | 2012 |
| Dedham Vale Enterprises Limited | Information & communication | 2021 |
| Dedham Vale Tree Surgery Limited | Agriculture & fishing | 2017 |
| Dedham Vale Vineyard Limited | Manufacturing | 2025 |
| Dedicated Design Ltd | Professional & scientific | 2026 |
| DEE Developments (UK) Limited | Real estate | 2012 |
| Dee-Zeed Health Care Ltd | Health & social care | 2019 |
| Deekay Solutions Limited | Wholesale & retail | 2010 |
| Deen Clothing Company Ltd | Wholesale & retail | 2025 |
| Deep Blue Media Services Limited | Information & communication | 2019 |
| Deep Cool Blue Building Services Limited | Construction | 2013 |
| Deep CUT Industries Ltd | Information & communication | 2026 |
| Deep Insight Radiology Ltd | Health & social care | 2025 |
| Deep Roots Essex Limited | Wholesale & retail | 2025 |
| Definitely Day-By-Day Care Limited | Health & social care | 2024 |
| Dejah Legal Ltd | Professional & scientific | 2016 |
| Dejays Homes and Properties Ltd | Construction | 2026 |
| Delectus Catering Ltd | Hospitality | 2022 |
| Deleste Limited | Real estate | 1998 |
| Deleste Productions Limited | Information & communication | 2000 |
| Deli Basha Coffe Ltd | Hospitality | 2023 |
| Delian Systems Limited | Information & communication | 1989 |
| Deliver More Projects Limited | Administrative & support | 2015 |
| Delivetts & Co. LLP | | 2024 |
| Dell G Ltd | Other services | 2025 |
| Dellonda Limited | Wholesale & retail | 2019 |
| Delta First Building Services Limited | Construction | 2026 |
| Delta Properties UK Limited | Real estate | 2008 |
| Delta T Mechanical and Electrical Limited | Construction | 2014 |
| Delta T Renewables Limited | Construction | 2011 |
| Delta T Services Limited | Other services | 2000 |
| Delta VAC Ltd | Other services | 2020 |
| Delta Works Limited | Construction | 2024 |
| Deltapoint Holdings Ltd | Wholesale & retail | 2017 |
| Deltawave Limited | Information & communication | 2015 |
| Deluxe Sign Services Ltd | Manufacturing | 2019 |
| Demand Cars Ltd | Wholesale & retail | 2022 |
| Demes Motorsports Ltd | Manufacturing | 2023 |
| Demeter Technical Services Ltd | Professional & scientific | 2026 |
| Demir C Ltd | Hospitality | 2024 |
| Demm Investments Limited | Real estate | 2022 |
| Demon Dojo Studio Ltd | Professional & scientific | 2026 |
| Demoshop Limited | Information & communication | 2025 |
| Demystify Communications Group Limited | Professional & scientific | 2020 |
| Dench Limited | Wholesale & retail | 2022 |
| Deneil Investments Limited | Construction | 2025 |
| Denni Luxe Limited | Manufacturing | 2025 |
| Dennis and SON Flooring Ltd | Construction | 2018 |
| Dennyg Limited | Construction | 2017 |
| Dent Devils Limited | Wholesale & retail | 1994 |
| Dental Companion Ltd | Information & communication | 2008 |
| Dental Partners Limited | Health & social care | 2007 |
| Dents & Scuffs Limited | Wholesale & retail | 2014 |
| Depend-Enable Ltd | Education | 2020 |
| Derm Hong Limited | Professional & scientific | 2025 |
| Dermanatural Ltd | Wholesale & retail | 2019 |
| Dermavivid Ltd | Health & social care | 2023 |
| Deruliniam Ltd | Information & communication | 2022 |
| DES Pearce (Flooring Specialists) Limited | Construction | 2004 |
| Design Assemblyuk Limited | Professional & scientific | 2025 |
| Design by CB Limited | Professional & scientific | 2023 |
| Design FX Studio Limited | Administrative & support | 2002 |
| Design Kinetic Ltd | Other services | 2007 |
| Designbyadam Ltd | Professional & scientific | 2018 |
| Designdd Construction Ltd | Construction | 2020 |
| Designer French Furniture Ltd | Wholesale & retail | 2012 |
| Designer Windows and Building Services Limited | Construction | 2026 |
| Designplus (Engineering) Limited | Professional & scientific | 2001 |
| Designsplus Essex Ltd. | Professional & scientific | 2017 |
| Desmonds Services Limited | Health & social care | 2023 |
| Destech Innovation Ltd | Information & communication | 2026 |
| Destination Colchester Community Interest Company | Other services | 2009 |
| Destoy Ltd | Real estate | 2023 |
| Detail GFX Ltd | Professional & scientific | 2020 |
| Detailed Quality Cleaning Services Ltd | Administrative & support | 2026 |
| Deus EX Natura Ltd | Manufacturing | 2021 |
| Developervillage Limited | Information & communication | 2021 |
| Devereux Court Limited | Real estate | 2004 |
| Devereux Electrical Services Limited | Construction | 2014 |
| Devitt Estates Ltd | Real estate | 2020 |
| Devlin INK Ltd | Other services | 2025 |
| Devon Interiors & Contractors Kitchens Ltd | Construction | 2024 |
| Devos Upholstery Ltd | Other services | 2022 |
| Devost Limited | Financial services | 2025 |