| Deja! Online Limited | Administrative & support | 2017 |
| Delancey Investment Group Limited | Real estate | 2025 |
| Delancey Oilfield Supplies Limited | Wholesale & retail | 2017 |
| Delaport Holdings Limited | Financial services | 2024 |
| Delaport Investments (Henley) Limited | Real estate | 2000 |
| Delaport Investments (Weymouth) Limited | Construction | 2019 |
| Delco Limited | Information & communication | 2003 |
| Delta-Tee Limited | Wholesale & retail | 2000 |
| Dementia Active Sussex CIC | Other services | 2024 |
| Demirhan Properties Ltd | Real estate | 2024 |
| Denby Finch Ltd | Professional & scientific | 2018 |
| Denisa Telecom Limited | Wholesale & retail | 2020 |
| Denmar Partnership Limited | Professional & scientific | 2013 |
| Denne Park Avenue Limited | Households | 1952 |
| Denne Park House (Management) Limited | Households | 1964 |
| Denne Properties Limited | Real estate | 2001 |
| Denne Services Limited | Administrative & support | 2023 |
| Dennis Constant Ltd | Professional & scientific | 2012 |
| Dental 360 Ltd | Health & social care | 2023 |
| Dental Healthcare Practice Limited | Health & social care | 2007 |
| Dentons Automotive Services Limited | Wholesale & retail | 2009 |
| Depiair Limited | Administrative & support | 1967 |
| Derma Beauty Academy Ltd | Other services | 2022 |
| Derma Beauty Clinic Ltd | Health & social care | 2020 |
| Derma Beauty Group Ltd | Financial services | 2022 |
| Derventium Properties Limited | Professional & scientific | 2002 |
| Desidev Enterprises Limited | Wholesale & retail | 2018 |
| Design Holidays Ltd | Hospitality | 2020 |
| Desryachri Limited | Wholesale & retail | 2025 |
| Detraco Properties Ltd | Real estate | 2025 |
| Deviate Digital Ltd | Professional & scientific | 2017 |
| Devinvest Limited | Real estate | 2023 |
| Devon Atlantic Limited | Information & communication | 2020 |
| Devonshire Bond Limited | Information & communication | 2013 |
| DF Finance Direction Limited | Professional & scientific | 2009 |
| DFA Progresso Ltd | Wholesale & retail | 2019 |
| DFX Smart Repair Ltd | Wholesale & retail | 2021 |
| DG Offshore Services Limited | Professional & scientific | 2023 |
| DG Solutions (Europe) Limited | Professional & scientific | 2018 |
| DG92 Consulting Limited | Professional & scientific | 2017 |
| Dghrrs Ltd | Hospitality | 2025 |
| Dgtol Ltd | Wholesale & retail | 2023 |
| DH Aviation Training Limited | Education | 2015 |
| DH Daza Investments Limited | Real estate | 2022 |
| Diagnostics Hub Limited | Health & social care | 2024 |
| Diamond Properties (Sussex) Limited | Real estate | 2021 |
| Diel's Food Ltd. | Manufacturing | 2015 |
| Dienn's Law Limited | Professional & scientific | 2020 |
| Different Cloth Ltd | Information & communication | 2009 |
| Different League Ltd | Administrative & support | 2023 |
| Different Tuna Ltd | Information & communication | 2010 |
| Difts Media Ltd | Information & communication | 2026 |
| Digi-Pay Ltd | Financial services | 2019 |
| Digital Camera Security Limited | Administrative & support | 2009 |
| Digital Camera Security UK Limited | Information & communication | 2007 |
| Digital Communications Network Solutions Ltd | Information & communication | 2014 |
| Digital Design Solutions Ltd | Professional & scientific | 2026 |
| Digital Display Solutions Limited | Professional & scientific | 2025 |
| Digital Flight Ltd | Information & communication | 2021 |
| Digital Innovation Partners Limited | Information & communication | 2015 |
| Digital Marketing Audit Ltd | Professional & scientific | 2016 |
| Digital Mixed Ltd | Other services | 2018 |
| Digital Munkeys Installations Limited | Information & communication | 2013 |
| Digital Pencil Case Ltd | Education | 2017 |
| Digital TOO Consultancy Ltd | Information & communication | 2015 |
| Digittop Limited | Agriculture & fishing | 1997 |
| Dimms Quantity Surveying Ltd | Professional & scientific | 2009 |
| Dimz Inc Ltd | Information & communication | 2018 |
| Dirae Ltd | Information & communication | 2024 |
| Direct Commercial Repairs Ltd | Manufacturing | 2011 |
| Direct Security Partnership Ltd | Construction | 2003 |
| DIRECT2WORK Limited | Administrative & support | 2007 |
| Directbranch Limited | Real estate | 1984 |
| Discovery Offshore Ltd | Wholesale & retail | 2024 |
| Diva Lighting Limited | Manufacturing | 1997 |
| Divon Auto Trade Limited | Wholesale & retail | 2026 |
| Dizon Healthcare Limited | Health & social care | 2013 |
| DJC Health Ltd | Professional & scientific | 2014 |
| DJD Transport (Horsham) Limited | Transport & logistics | 2017 |
| Djkc Limited | Information & communication | 2010 |
| DK Aviation Limited | Professional & scientific | 2026 |
| DK Projects Limited | Construction | 2020 |
| DKT Aviation Ltd | Professional & scientific | 2018 |
| DLR Construction Ltd | Construction | 2023 |
| DLS Landscaping & Maintenance Ltd | Administrative & support | 2026 |
| DM Handyman Services Limited | Construction | 2014 |
| DM Wilbury Limited | Professional & scientific | 2020 |
| DM Window Cleaning Ltd | Administrative & support | 2025 |
| DMA Building Designs Ltd | Construction | 2014 |
| DMA Business Services Limited | Professional & scientific | 2013 |
| DMS Landscaping & Garden Rooms Ltd | Administrative & support | 2022 |
| DN Publications Limited | Information & communication | 2007 |
| DOE Caravans Transport Limited | Transport & logistics | 2012 |
| DOE Trading Ltd | Real estate | 2026 |
| Dog Hotel Ltd | Other services | 2012 |
| Dogcity Ltd | Information & communication | 2023 |
| Dogmersfield Park Estate Ltd | Agriculture & fishing | 2024 |
| Doku Games Ltd | Arts & recreation | 2015 |
| Domenica Limited | Wholesale & retail | 2011 |
| Domenico Landolfi Creative Ltd | Professional & scientific | 2019 |