| DE Sousa Surwald Ltd | Manufacturing | 2009 |
| Deacon Properties (Tunbridge Wells) Ltd | Real estate | 2009 |
| Deacon Stemp Brickwork Limited | Construction | 2024 |
| Deacon Stemp Holdings Limited | Real estate | 2024 |
| Deacon Stemp Limited | Construction | 2012 |
| Dealmakers Corporate Finance Limited | Financial services | 2014 |
| Dean & Co Estate Agents and Valuers Limited | Administrative & support | 2014 |
| Dean Lewis Architects Ltd | Professional & scientific | 2017 |
| Death to Decaf Ltd | Hospitality | 2015 |
| Deaves & Co (Installations) Limited | Construction | 1996 |
| Deaves & Co. Home Improvements Limited | Construction | 1978 |
| Debbie James Consulting Ltd | Information & communication | 2025 |
| Debby Newman Marketing Ltd | Professional & scientific | 2025 |
| Debra Gilbert Therapy Ltd | Health & social care | 2022 |
| Decamp Ltd | Wholesale & retail | 2023 |
| Decentragrid Ltd | Professional & scientific | 2024 |
| Deckchair Solutions Limited | Information & communication | 2012 |
| Decomplicate Limited | Professional & scientific | 2013 |
| Dedo Brighton Limited | Hospitality | 2024 |
| Deep Blue Safety Ltd | Professional & scientific | 2024 |
| Definitive Television Limited | Information & communication | 2002 |
| Deft Creative Ltd | Information & communication | 2003 |
| Dekels Properties Limited | Real estate | 2024 |
| Delano Electronics Limited | Information & communication | 2011 |
| Delano LLP | | 2005 |
| Delbe Property Limited | Real estate | 2012 |
| Delve Deep Ltd | Information & communication | 2020 |
| Demiraydin Butcher Ltd | Wholesale & retail | 2019 |
| Demirdag Hove Limited | Other services | 2013 |
| Denco Holdings Ltd | Financial services | 2026 |
| Deneb Ltd | Health & social care | 2024 |
| Deneb Property Limited | Real estate | 2020 |
| Denes Rottingdean Properties Limited | Real estate | 2000 |
| Deniz & ADA Limited | Construction | 2024 |
| Denmark Villas Limited | Households | 1994 |
| Dental Craft by Stephanie Ltd | Health & social care | 2021 |
| Dental Excel Limited | Education | 2020 |
| Dental Nurse Network Limited | Education | 2012 |
| Dental Oriental Limited | Health & social care | 2022 |
| Dentesthet Limited | Health & social care | 2015 |
| Denticle Limited | Health & social care | 2020 |
| Dentistry by Richard Coates Limited | Health & social care | 2019 |
| Dentl Limited | Health & social care | 2023 |
| DEP Associates Ltd | Information & communication | 2009 |
| Derek Crowson Limited | Professional & scientific | 1986 |
| Dermaenhance Ltd. | Wholesale & retail | 2012 |
| Derwent Management Company Limited | Real estate | 1974 |
| DES Jabir Productions Limited | Arts & recreation | 2009 |
| Descreco Ltd | Professional & scientific | 2013 |
| Design 45 Ltd | Professional & scientific | 2021 |
| Design Interiors (Hove) Limited | Extraterritorial | 2009 |
| Design Interiors Limited | Wholesale & retail | 1993 |
| Design Quarter Management Limited | Other services | 2004 |
| Designed Investment Limited | Financial services | 2025 |
| Detag Ltd | Administrative & support | 2020 |
| Detail Flooring Limited | Construction | 2023 |
| Deutschecraft Ltd | Wholesale & retail | 2011 |
| Devils Bykes Limited | Manufacturing | 2021 |
| Devoy & Smallbone Properties Ltd | Real estate | 2016 |
| Devware Ltd | Information & communication | 2018 |
| Dewleaze Limited | Professional & scientific | 1985 |
| Dewmist Limited | Construction | 2012 |
| Deworde Ltd | Professional & scientific | 2017 |
| Dexter Investments Limited | Real estate | 2009 |
| DEZ REZ Properties Limited | Real estate | 1996 |
| Dfrg Ltd | Real estate | 2021 |
| DG Motorcycle Centre Ltd | Wholesale & retail | 2024 |
| DG Motorcycle Services and Repairs Ltd | Wholesale & retail | 2017 |
| DGH Property Ltd | Real estate | 2024 |
| DGP Security Ltd | Administrative & support | 2022 |
| DH Kitchens & Carpentry Ltd | Manufacturing | 2026 |
| DH York Limited | Health & social care | 2021 |
| DHA Contracting Limited | Professional & scientific | 2022 |
| Dharma Coffee Hove Ltd | Hospitality | 2024 |
| Dhyaan Limited | Health & social care | 2026 |
| DI Giovanni Limited | Manufacturing | 2024 |
| DI2 FAC Ltd | Health & social care | 2021 |
| Diamond Days Ltd | Hospitality | 2018 |
| Diamond Decor (GB) Ltd | Construction | 2013 |
| Diamond Dental Staff Limited | Health & social care | 2018 |
| Diamond Electrical Solutions (Brighton) Limited | Construction | 2020 |
| Diamond Wholesale Limited | Wholesale & retail | 2001 |
| Diana Dent Limited | Health & social care | 2018 |
| Diego & Friends Ltd | Other services | 2021 |
| Diego Hospitality Services UK Ltd | Hospitality | 2024 |
| Dier Enterprises Limited | Professional & scientific | 2013 |
| Dietmedica Ltd | Professional & scientific | 2015 |
| Difference Digital Ltd | Information & communication | 2007 |
| Different Strokes for Different Folks Ltd | Information & communication | 2024 |
| Different Vision International Company Ltd | Administrative & support | 2023 |
| Differing Minds CIC | Professional & scientific | 2021 |
| DIG Deep Communications Ltd | Extraterritorial | 2020 |
| Digi-Board Limited | Administrative & support | 2017 |
| DIGI2AL Limited | Information & communication | 2013 |
| Digital Gurus Ltd | Information & communication | 2012 |
| Digital Health Compliance Ltd | Information & communication | 2023 |
| Digital Innovation Studios Limited | Information & communication | 2023 |
| Digital-Writes Limited | Information & communication | 2013 |
| Digitv Limited | Administrative & support | 2007 |
| Dillion&Co Ltd | Other services | 2011 |