| Deeper Green Limited | Professional & scientific | 2020 |
| Definitely T Ltd | Wholesale & retail | 2024 |
| Delage & Haughton Limited | Extraterritorial | 2018 |
| Delavals Limited | Construction | 1978 |
| Delicious House Limited | Hospitality | 2016 |
| Deniston Properties (Hove) Limited | Construction | 1966 |
| Dentstone Limited | Hospitality | 2015 |
| Dersingham Road Holdings Limited | Real estate | 1945 |
| Design From Space Limited | Professional & scientific | 2020 |
| Design Initiative Limited | Manufacturing | 1980 |
| Design Prosthetics Limited | Health & social care | 2016 |
| Designraphael Limited | Professional & scientific | 2003 |
| Development Crew Ltd | Information & communication | 2013 |
| Development Management Associates CIC | Professional & scientific | 2019 |
| Dhara Associates Limited | Professional & scientific | 2010 |
| Didacious Designs Ltd. | Professional & scientific | 1998 |
| Diggers & Enthusiasts CIC | Arts & recreation | 2025 |
| Digitally Human Ltd | Administrative & support | 2016 |
| Dilan Soylu Ltd | Hospitality | 2026 |
| Dimple Discs Limited | Arts & recreation | 2020 |
| DIMSUM4U Ltd | Hospitality | 2021 |
| Direct Business Finance Limited | Financial services | 2001 |
| Direct Mortgage Group Limited | Financial services | 2000 |
| Disabled NOT Dead Presents CIC | Arts & recreation | 2025 |
| Discountcomms Limited | Wholesale & retail | 2005 |
| Discover and BE Ltd | Education | 2016 |
| Ditchling Beacon and Commons | Administrative & support | 2017 |
| Diveblue Ltd | Arts & recreation | 2025 |
| Divelab Ltd | Wholesale & retail | 2025 |
| Diversity HR Limited | Administrative & support | 2009 |
| Diversity Property Ltd | Financial services | 2023 |
| Diversity Resource International (DRI) C.I.C. | Education | 2004 |
| Divine Teas Ltd | Households | 2022 |
| Diya Partnership Limited | Information & communication | 1998 |
| DK Renovation Ltd | Construction | 2018 |
| DNA Universal Limited | Professional & scientific | 2018 |
| Docwra Ltd | Professional & scientific | 2011 |
| Dolly Clothing Limited | Other services | 2019 |
| Dominic Harris Lettings Ltd | Real estate | 2025 |
| Don'T Urbanise the Downs Ltd | Other services | 2023 |
| Doodah Theatre | Arts & recreation | 2002 |
| Dotco Ltd | Information & communication | 2009 |
| Downsizing Media Limited | Information & communication | 2019 |
| Downsview Dairy Produce Ltd. | Manufacturing | 2011 |
| Downsview Management Company Limited | Households | 2008 |
| DP Productions Ltd | Arts & recreation | 2024 |
| DR. Gabriella Ltd | Health & social care | 2024 |
| Drablow Holdings Ltd | Financial services | 2025 |
| Dragons Dream Limited | Information & communication | 1981 |
| Drakes Plastering & Rendering Ltd | Construction | 2025 |
| Drunk Monkey Limited | Hospitality | 2015 |
| Drunk Monkey Properties Limited | Real estate | 2017 |
| Dual CAD Services Limited | Construction | 2012 |
| Dudley Hunter Limited | Wholesale & retail | 2002 |
| Dwaraka Catering Ltd | Hospitality | 2026 |
| Dwaraka Hotels Ltd | Hospitality | 2026 |
| DWD Communications Ltd | Professional & scientific | 2022 |
| E10 Luxury Sport & Travel Limited | Administrative & support | 2023 |
| Eagle EYE Studios - 360FLICKS.COM Limited | Information & communication | 2009 |
| Eagle Private Ltd | Administrative & support | 2023 |
| Earsham Estate Office Limited | Professional & scientific | 1981 |
| East Hoathly and Halland Community Garden C.I.C. | Health & social care | 2015 |
| East Park Estates Limited | Real estate | 2017 |
| East Sussex Dance Ltd | Education | 2009 |
| East Sussex Smallholders Ltd | Agriculture & fishing | 2023 |
| East to South East | Administrative & support | 1998 |
| Eastwood H&P Limited | Construction | 2025 |
| Eco Skip Waste & Recycling Ltd | Water & waste | 2018 |
| Eden & Partners Consultancy Limited | Professional & scientific | 2013 |
| Eden Landscapes East Sussex Ltd | Administrative & support | 2025 |
| Eden Pubs Limited | Hospitality | 2000 |
| Edenbrook Enterprises Limited | Real estate | 1999 |
| Edge Hill Entertainment Ltd | Arts & recreation | 2011 |
| Editors 4 Change Limited | Other services | 2008 |
| Education, Health & Wellbeing Community Interest Company | Health & social care | 2019 |
| Edward Street Flats Limited | Real estate | 2024 |
| Edwards & Todd Limited | Wholesale & retail | 2002 |
| EDWARDS1999 Limited | Professional & scientific | 2021 |
| Eezadyl Limited | Financial services | 2017 |
| EF HR & Payroll Solutions Ltd | Administrative & support | 2021 |
| EFT Electrical Limited | Wholesale & retail | 2012 |
| EG Impact Ltd | Professional & scientific | 2018 |
| Einstein's Attic Limited | Information & communication | 2000 |
| Electric Sunshine Limited | Professional & scientific | 2012 |
| Eleven Group Global Limited | Professional & scientific | 2020 |
| Elhinn's Shoe Gallery Limited | Wholesale & retail | 2003 |
| Elite Vending Ltd | Wholesale & retail | 2026 |
| Ellen Brookes Trend Consultancy Ltd | Professional & scientific | 2012 |
| Ellis Seabrook Limited | Professional & scientific | 2018 |
| Ellis Structures Limited | Professional & scientific | 2014 |
| ELM Court (Seaford) Limited | Construction | 2018 |
| ELM Court Residents Blatchington Limited | Households | 2026 |
| Elphick & SON Limited | Real estate | 1909 |
| Ember Public Relations Ltd | Professional & scientific | 2024 |
| Embrace Psychology Sussex Limited | Health & social care | 2021 |
| Emde Limited | Extraterritorial | 1993 |
| Emerville Limited | Households | 1995 |
| EMF Consultancy Ltd | Public administration | 2026 |
| Emily Design Co Ltd | Professional & scientific | 2026 |
| Emizz Limited | Construction | 2020 |