| Discovery Ultrasound Kent & Sussex Limited | Health & social care | 2013 |
| Dispatched Discounts Ltd | Wholesale & retail | 2025 |
| Distinguished Dentalmen Limited | Health & social care | 2018 |
| Dittons Corner Management Company Limited | Households | 2017 |
| Ditzy Media Ltd | Professional & scientific | 2017 |
| Diversified Ventures Ltd | Manufacturing | 2020 |
| Divine Clean Ltd | Administrative & support | 2018 |
| Dixon Court RTM Company Limited | Hospitality | 2006 |
| Dizzy Piggy Catering Limited | Hospitality | 2016 |
| DJA Advisory Ltd | Professional & scientific | 2023 |
| DJM Roofing Eastbourne Limited | Construction | 2024 |
| DJS Consulting Ltd | Professional & scientific | 2025 |
| DJT Projects Limited | Information & communication | 2012 |
| DJWILLS8 Ltd | Construction | 2018 |
| DK Maintenance Eastbourne Limited | Manufacturing | 2019 |
| DK Platinum Properties Ltd | Real estate | 2026 |
| DKI Litehouse Ltd | Manufacturing | 2016 |
| DKM Paintworks Ltd | Wholesale & retail | 2026 |
| DL Carpentry & Construction Ltd | Administrative & support | 2026 |
| DL Dermnet Ltd | Health & social care | 2017 |
| DL Docks Ltd | Hospitality | 2022 |
| DL East Ltd | Financial services | 2026 |
| DL Food & Drink Ltd | Hospitality | 2020 |
| DL Management Holdings Ltd | Construction | 2024 |
| DL South Ltd | Hospitality | 2022 |
| DL Space Ltd | Hospitality | 2018 |
| DLF Consulting and Services Limited | Construction | 2011 |
| DLF Driveway & Construction Ltd | Construction | 2021 |
| DLS Dental Care Limited | Health & social care | 2012 |
| DM BIM81 Ltd | Professional & scientific | 2025 |
| DMC Global Holdings Limited | Financial services | 2019 |
| DMC Procurement Limited | Construction | 2020 |
| DMC Residential Projects Ltd | Construction | 2019 |
| DMD Capital Limited | Hospitality | 2008 |
| Dmdpro Ltd | Construction | 2026 |
| DMO Investments Limited | Real estate | 2019 |
| DMR Eastbourne Properties Limited | Real estate | 2023 |
| DNA Code Limited | Information & communication | 1993 |
| DNB Stellar Trading Ltd | Wholesale & retail | 2024 |
| DO Electrical Services Ltd | Construction | 2015 |
| Doctor Karaca Limited | Hospitality | 2022 |
| Dodia Limited | Professional & scientific | 2015 |
| Dojo Systems Limited | Wholesale & retail | 2026 |
| Dolltox Aesthetics Limited | Other services | 2026 |
| Dolphin Court Meads Limited | Households | 2023 |
| Dolphin Fish Bar Limited | Hospitality | 2020 |
| Domarex UK Ltd | Wholesale & retail | 2014 |
| Dominic Hill Associates Limited | Professional & scientific | 1993 |
| Dominic Hill Ltd | Extraterritorial | 2017 |
| Domino World Transport Limited | Transport & logistics | 2009 |
| Domsalla Building Services Limited | Construction | 2004 |
| Dondarrion Services Limited | Administrative & support | 2017 |
| Done and Dusted BTN Limited | Administrative & support | 2015 |
| Dopigo Ltd | Transport & logistics | 2021 |
| Doran Medical Services Limited | Health & social care | 2025 |
| Dorchester Court (Eastbourne) Limited | Households | 1999 |
| Dorchester Court Residents Association Limited | Households | 2005 |
| Doshmak PVT Ltd | Health & social care | 2025 |
| Double Decker Productions Ltd | Information & communication | 2015 |
| Double U Double O Ltd | Administrative & support | 2022 |
| Dough Science Ltd | Wholesale & retail | 2025 |
| Douglas Builders (UK) Limited | Construction | 2004 |
| Douglas Hamilton Estates (Southern) Limited | Construction | 2001 |
| Doves Yard Limited | Households | 2016 |
| Dowling Nash Limited | Health & social care | 2025 |
| Down LOW Limited | Transport & logistics | 2019 |
| Downlands (Willingdon) Limited | Households | 1959 |
| Downlands Properties Limited | Real estate | 2022 |
| Downs Garage Limited | Wholesale & retail | 2015 |
| Downsview (Eastbourne) Limited | Households | 2004 |
| Downtown Deli SC Ltd | Hospitality | 2025 |
| Dowsett Associates Limited | Professional & scientific | 2011 |
| DP Fuel Tank Services Limited | Administrative & support | 1966 |
| DP Goodwin Developments Limited | Construction | 2021 |
| DPF Power Ltd | Manufacturing | 2019 |
| DR a Dangoor Ltd | Health & social care | 2019 |
| DR Ajeena Limited | Health & social care | 2026 |
| DR an Shah Ltd | Health & social care | 2024 |
| DR B Foster Child & Educational Psychology Services Ltd | Education | 2026 |
| DR C I Okocha Limited | Administrative & support | 2011 |
| DR Cedrola Limited | Health & social care | 2024 |
| DR Daniel Krahne Limited | Health & social care | 2016 |
| DR H&C Ltd | Health & social care | 2024 |
| DR Hart Medicolegal Ltd | Professional & scientific | 2024 |
| DR Hart Neurology Limited | Health & social care | 2011 |
| DR Jacob Ltd | Health & social care | 2012 |
| DR James Woolley Limited | Health & social care | 2012 |
| DR John Morley Limited | Health & social care | 2012 |
| DR Josh Bernard Spencer Limited | Health & social care | 2025 |
| DR Krishan Mistry Limited | Health & social care | 2021 |
| DR LT Associates Ltd | Health & social care | 2022 |
| DR Lucja Zgudka Smile Ltd | Administrative & support | 2026 |
| DR Motox Limited | Health & social care | 2019 |
| DR Motox Products Ltd | Wholesale & retail | 2021 |
| DR Motox Property Limited | Real estate | 2025 |
| DR Paul Carter Limited | Health & social care | 2012 |
| DR Pratish Facial Aesthetics Limited | Health & social care | 2021 |
| DR Raheel Malik Limited | Health & social care | 2012 |
| DR Richard Field Limited | Health & social care | 2013 |
| DR S Maghsoudi Ltd | Health & social care | 2010 |