| Double Take Studios Ltd | Information & communication | 2024 |
| Doubleday (Farms) Limited | Agriculture & fishing | 1962 |
| Doubleday Gardens Management Company Limited | Households | 2019 |
| Douglas .a. Reed & Associates Ltd. | Professional & scientific | 1978 |
| Douglas Curtis Machine Tools (Colchester) Limited | Professional & scientific | 1973 |
| Douglas Electrical Contractors Limited | Construction | 2017 |
| Douglas Management Limited | Real estate | 1971 |
| Doula UK CIC | Health & social care | 2008 |
| Dove Films Limited | Information & communication | 2007 |
| Dove Leisure Ltd | Hospitality | 2024 |
| Down at the Cabin Ltd | Education | 2017 |
| Downes Ltd | Real estate | 2015 |
| DP Professional Staff Limited | Administrative & support | 2016 |
| DPA Bakery Ltd | Manufacturing | 2023 |
| Dpatey Limited | Construction | 2018 |
| DPC Digital Solutions Limited | Information & communication | 2022 |
| DPE Group Ltd | Administrative & support | 2025 |
| DPF Solutions Ltd | Wholesale & retail | 2017 |
| Dponle Properties Ltd | Real estate | 2020 |
| DQA Management Company Limited | Households | 2015 |
| DR Alison RAM Ltd | Health & social care | 2024 |
| DR and MRS Bulacz Ltd | Professional & scientific | 2020 |
| DR Autofleet Solutions Ltd | Wholesale & retail | 2025 |
| DR Beth Pasfield Dent Ltd | Health & social care | 2025 |
| DR Charles Greensmith Dent Ltd | Health & social care | 2025 |
| DR Essex Ltd | Information & communication | 2019 |
| DR Hashem Colchester Aesthetics Ltd | Health & social care | 2022 |
| DR Jean Raymond Ltd | Administrative & support | 2018 |
| DR KOT Medical Ltd | Health & social care | 2023 |
| DR M Scoote Ltd | Health & social care | 2023 |
| DR N Aravindhan Ltd | Health & social care | 2011 |
| DR N Robinson Limited | Health & social care | 2010 |
| DR Peter Hawkins Limited | Health & social care | 2014 |
| DR RAM Consultants Limited | Health & social care | 2014 |
| DR Shenoy Limited | Health & social care | 2015 |
| DR Skin Central Ltd | Health & social care | 2024 |
| DR Steve Ellis Chest Radiologist Ltd | Health & social care | 2022 |
| DR SYD Hiskey and Associates Ltd | Health & social care | 2017 |
| DR. C. Andersson Limited | Professional & scientific | 2015 |
| DR. Simon Ralphs Ltd | Health & social care | 2022 |
| Draco (Chelmsford) Limited | Other services | 2011 |
| Drag Iancu Ltd | Construction | 2019 |
| Dragon Supplies UK Ltd | Wholesale & retail | 2007 |
| Dragon Tactical Limited | Wholesale & retail | 2019 |
| Dragonfly Advisory Ltd | Financial services | 2024 |
| Dragonfly Holdings Ltd | Information & communication | 2018 |
| Dragonfly Lounge Limited | Hospitality | 2023 |
| Dragonfly Topco Ltd | Financial services | 2024 |
| Drainage Sales Ltd | Extraterritorial | 2012 |
| Draincore Ltd | Water & waste | 2026 |
| Drainmaintain Limited | Water & waste | 2024 |
| Draught Services Ltd | Wholesale & retail | 2016 |
| Drawing Inc Limited | Professional & scientific | 2017 |
| Drawly Competitions Ltd | Wholesale & retail | 2026 |
| Draydon Cottages Management Company Limited | Households | 2004 |
| Drayton Utilities Ltd | Construction | 2019 |
| Dream Fishing Holidays Limited | Arts & recreation | 2008 |
| Dream Pathway Academy Limited | Arts & recreation | 2024 |
| Dream the Change CIC | Education | 2019 |
| Dreamaura Ltd | Wholesale & retail | 2026 |
| Dreambuy Ltd | Wholesale & retail | 2020 |
| Dreamhsa PVT Ltd | Real estate | 2025 |
| Dreamwave Group Ltd | Arts & recreation | 2013 |
| Dresdner Innovation Management Limited | Financial services | 2005 |
| Dress Code Nine (Earls Colne) Ltd | Wholesale & retail | 2022 |
| Driem Ltd | Financial services | 2022 |
| Driftco Limited | Households | 2025 |
| Drill Technics Ltd | Construction | 2012 |
| Drivehub Colchester Ltd | Wholesale & retail | 2026 |
| Driveland Estates Limited | Real estate | 2001 |
| Driven Refinish Supplies Ltd | Wholesale & retail | 2024 |
| Drivers Hire Limited | Transport & logistics | 2023 |
| Drivers Supply Limited | Transport & logistics | 2023 |
| Drivest Limited | Information & communication | 2026 |
| DRJ Services Limited | Construction | 2001 |
| DRK Private Limited | Wholesale & retail | 2023 |
| Drointon Solar Farm Limited | Energy | 2022 |
| Drone Sight Ltd | Professional & scientific | 2023 |
| Drory Consultancy Limited | Information & communication | 2014 |
| Drpp 2018 Ltd | Construction | 2018 |
| Drugloo (UK) Ltd | Administrative & support | 2007 |
| Drugloo International Limited | Manufacturing | 2016 |
| Drum UP Wear Ltd | Wholesale & retail | 2025 |
| Drumatree Limited | Financial services | 2025 |
| Drumbell Technologies Limited | Information & communication | 2024 |
| Drummers Heritage Arts Studio Ltd | Arts & recreation | 2024 |
| Drunken Duck Ltd | Hospitality | 2025 |
| Drury Healthcare Limited | Health & social care | 2017 |
| DRW Plumbing & Heating Ltd | Construction | 2019 |
| Drxt Signalling Services Ltd | Construction | 2021 |
| Dryden House Ltd | Other services | 2023 |
| Drylining Material Loaders Limited | Construction | 2021 |
| Drylining Solutions Limited | Construction | 2025 |
| DS Chambers Transport Limited | Transport & logistics | 2023 |
| DS Expert Witness Services Ltd | Professional & scientific | 2025 |
| DSD Groundworks Ltd | Construction | 2023 |
| DSG Developments Limited | Construction | 2014 |
| Dside Design Ltd | Manufacturing | 2019 |
| Dsignd Studios Ltd | Information & communication | 2026 |
| DSL Holdings Group Ltd | Real estate | 2024 |