| Debt Independent Ltd | Administrative & support | 2015 |
| Deca Design Ltd | Other services | 2012 |
| Decastro Investments Ltd | Real estate | 2021 |
| Deckard Properties Limited | Real estate | 2015 |
| Decod Ltd | Other services | 2023 |
| Decorate NOW Ltd | Wholesale & retail | 1992 |
| Decorators Warehouse Limited | Wholesale & retail | 1995 |
| Decoro Decorating & Property Maintenance Ltd | Construction | 2022 |
| Deenova Services Limited | Administrative & support | 2021 |
| Deep & Sheena Jethwa Ltd | Health & social care | 2019 |
| Deep Blue Charters Limited | Administrative & support | 2021 |
| Deep DOM Ltd | Professional & scientific | 2021 |
| Deep Enterprice Limited | Wholesale & retail | 2023 |
| Deep Intellect Ltd | Professional & scientific | 2016 |
| Deep Quality Food Ltd | Hospitality | 2024 |
| Deep Valley Limited | Professional & scientific | 2015 |
| Deerwood Construction Ltd | Construction | 2021 |
| Deerwork Ltd | Agriculture & fishing | 2012 |
| Defiant Sports C.I.C. | Education | 2017 |
| Degg General Builders Limited | Construction | 2019 |
| Deja VU Eastbourne Ltd | Hospitality | 2014 |
| DEL IT Ltd | Information & communication | 2025 |
| Delamere Court (Eastbourne) Residents Association Limited | Households | 1960 |
| Delite Group Ltd | Hospitality | 2017 |
| Dell Quay Consultants Limited | Financial services | 1987 |
| Delmic Developments Limited | Construction | 1978 |
| Delta Capricorni UK Limited | Other services | 2024 |
| Deluna Driveways Ltd | Construction | 2021 |
| DEM Food Ltd | Hospitality | 2022 |
| Demeter Associates Ltd | Professional & scientific | 2024 |
| Demon Blue LLP | | 2011 |
| Demon Blue Music LLP | | 2012 |
| Denbe Properties Limited | Real estate | 2023 |
| Dene Lodge Dental Practice Limited | Health & social care | 2023 |
| Dene Place 26 ST Leonards Road Management Limited | Households | 2000 |
| Denis Bonnici Electricians Limited | Construction | 2007 |
| Denma Cleaning Services Limited | Administrative & support | 1988 |
| Dentacare OSI Ltd | Health & social care | 2024 |
| Dental Care Studio Limited | Health & social care | 2026 |
| Dental Mosaic Limited | Health & social care | 2025 |
| Dentiverse Ltd | Information & communication | 2024 |
| Denton Mead Limited | Households | 1958 |
| Dentopedia Limited | Health & social care | 2013 |
| Dentopediagroup Limited | Health & social care | 2024 |
| Dentrica Ltd | Health & social care | 2018 |
| Desert Island Films Limited | Information & communication | 2007 |
| Desert Jane Ltd | Wholesale & retail | 2025 |
| Design Build Maintain Services Limited | Construction | 2016 |
| Design Create Adapt Limited | Professional & scientific | 2024 |
| Design LAB Signs & Print Ltd | Manufacturing | 2026 |
| DESIGN4U Construction Ltd | Construction | 2021 |
| Detailed Ltd | Administrative & support | 2018 |
| Deuces Padel Co. Ltd | Wholesale & retail | 2024 |
| Devea 2 Ltd | Construction | 2021 |
| Devea Lettings Ltd | Real estate | 2023 |
| Devea Limited | Construction | 2010 |
| Devea Properties LLP | | 2020 |
| Developing Minds Consultancy Ltd | Health & social care | 2026 |
| Devonshire Building Solutions Ltd | Construction | 2010 |
| Devonshire General Stores Ltd | Wholesale & retail | 2017 |
| Devonshire Lodge (Eastbourne) Limited | Real estate | 2015 |
| Devonshire Park Hotel Limited | Hospitality | 2001 |
| Devr Builders Limited | Construction | 2025 |
| Devris Property Services Limited | Real estate | 2018 |
| DEW Drop Inn Eastbourne Limited | Hospitality | 2019 |
| Dewbell Properties Limited | Real estate | 2013 |
| Dexter Management Services Ltd | Wholesale & retail | 2024 |
| DFT Healthcare Ltd | Health & social care | 2026 |
| DG Mercado Ltd | Professional & scientific | 2021 |
| DH Intent Ltd | Professional & scientific | 2020 |
| DH2 Home Improvements Limited | Manufacturing | 2022 |
| Dheer Management Limited | Real estate | 2024 |
| DHH (Eastbourne) Limited | Real estate | 2014 |
| DHR Window Repairs Limited | Construction | 2022 |
| DHY Teachers Training Academy (UK) Ltd | Education | 2017 |
| DI Hill Women's Empowerment Coach Ltd | Administrative & support | 2021 |
| Diallo Investments Limited | Real estate | 2024 |
| Diamansion Ltd | Real estate | 2024 |
| Diamond Car Cleaning Ltd | Other services | 2025 |
| Diamond Meds Limited | Wholesale & retail | 2021 |
| Diamond Windows and Gardens Limited | Administrative & support | 2011 |
| Dickonadamsdental Limited | Health & social care | 2021 |
| Didac Schools Limited | Education | 1999 |
| Digihall Ltd | Information & communication | 2024 |
| Digit Margin Ltd | Professional & scientific | 2022 |
| Digital AD Van Ltd | Wholesale & retail | 2018 |
| Digital Assembly Ltd | Information & communication | 2010 |
| Digital Assets Association United Kingdom | Other services | 2026 |
| Digital Communication Installations Limited | Professional & scientific | 2001 |
| Digital Consulting Services Limited | Professional & scientific | 2016 |
| Digital Heartbeat Ltd | Information & communication | 2014 |
| Digital Sparky Limited | Construction | 2018 |
| Digital Sports Coaching Limited | Information & communication | 2010 |
| Digital Urban Studios Ltd | Information & communication | 2025 |
| DIH PVT Ltd | Health & social care | 2022 |
| Dinkdown | Financial services | 2025 |
| Diocese of Chichester Academy Trust | Education | 2014 |
| Diorama Group Ltd | Real estate | 2022 |
| Direct Letting (South East) Limited | Real estate | 2000 |
| Dirty Word Limited | Information & communication | 2015 |