| Cutter Workwear Limited | Wholesale & retail | 2014 |
| Cylinder Limited | Arts & recreation | 1997 |
| D & G Medical Ltd | Health & social care | 2022 |
| D & L Associates Limited | Information & communication | 1997 |
| D a Mann Limited | Financial services | 2020 |
| D B K Consultant Limited | Construction | 2017 |
| D J Carpentry Limited | Manufacturing | 2025 |
| D J Ruse Builders Limited | Construction | 2020 |
| D N Martin Trans Ltd | Transport & logistics | 2022 |
| D P Agency Limited | Wholesale & retail | 2002 |
| D-Tech International Limited | Manufacturing | 2002 |
| D.E. Keeble Limited | Other services | 2007 |
| D.J. Mackenzies Limited | Wholesale & retail | 2003 |
| Dacecroft (Dereham) Limited | | 1978 |
| DAF Consultancy Limited | Professional & scientific | 2022 |
| DAH Driving Services Ltd | Transport & logistics | 2019 |
| Dales Property Limited | Real estate | 2007 |
| Dalestevens Consulting Limited | Professional & scientific | 2008 |
| Dapstar Engineering Limited | Construction | 2016 |
| Dark Soul Publishing Ltd | Information & communication | 2013 |
| Darnell Lettings Ltd | Real estate | 2026 |
| David Friend Heating Services Limited | Construction | 2010 |
| David Harwood-Little Ltd | Information & communication | 2023 |
| David Lynch Foundation UK | Education | 2012 |
| David Nice Agencies Limited | Wholesale & retail | 1977 |
| Davina Greenwell Property Management Limited | Real estate | 2022 |
| DAW Utilities Ltd | Agriculture & fishing | 2020 |
| Dawlin Limited | Wholesale & retail | 2014 |
| Dawson's Post Ltd | Information & communication | 2015 |
| Day Contracting Service Limited | Professional & scientific | 2017 |
| Daylilly Ltd | Wholesale & retail | 2026 |
| DBI Property Consultants Ltd | Real estate | 2003 |
| Dealer World Ltd | Information & communication | 2020 |
| Deap Indigo Limited | Information & communication | 2025 |
| Deben Aero Ltd | Professional & scientific | 2023 |
| Deben Bar Limited | Hospitality | 2018 |
| Deben Boatyard Ltd | Manufacturing | 1962 |
| Deben Cafe Limited | Hospitality | 2018 |
| Deben Capital Partners Limited | Professional & scientific | 2009 |
| Deben Community Farm Community Interest Company | Education | 2015 |
| Deben Dragonfly Ltd | Real estate | 2024 |
| Deben Electrical Services Ltd | Construction | 2022 |
| Deben Estates Limited | Administrative & support | 2010 |
| Deben Estuary Partnership Limited | Administrative & support | 2011 |
| Deben Health Group (PCN) Ltd | Health & social care | 2022 |
| Deben Holiday Homes Limited | Hospitality | 2025 |
| Deben Hose and Hydraulics Ltd | Administrative & support | 2012 |
| Deben Inns Limited | Hospitality | 1997 |
| Deben Ladies Fitness Limited | Arts & recreation | 2012 |
| Deben Landscapes Limited | Construction | 2009 |
| Deben Marine Limited | Manufacturing | 2004 |
| Deben Network Design Limited | Information & communication | 2001 |
| Deben Pest Solutions Ltd | Professional & scientific | 2023 |
| Deben Ponds Ltd | Administrative & support | 2015 |
| Deben Private GP Services Ltd | Health & social care | 2022 |
| Deben Transport Repairs Limited | Wholesale & retail | 2003 |
| Deben Travel Ltd. | Administrative & support | 2011 |
| Deben Watersports Centre | Arts & recreation | 2013 |
| Debenside Developments Ltd | Construction | 2022 |
| Debenvale of Woodbridge Limited | Wholesale & retail | 2013 |
| Decoy Studios Limited | Manufacturing | 2025 |
| Deepening Into Life Ltd | Health & social care | 2021 |
| DEM Group Ltd | Construction | 2014 |
| Dennington Contracting Limited | Agriculture & fishing | 2011 |
| Dereham Properties Limited | Real estate | 2016 |
| Derivative Consulting Limited | Professional & scientific | 2016 |
| Desert Frost Limited | Manufacturing | 2022 |
| DESIGN256 Limited | Manufacturing | 1996 |
| Diginym Ltd | Information & communication | 2023 |
| Digital Regs Ltd | Professional & scientific | 2025 |
| Dinemark Heating Limited | Extraterritorial | 1993 |
| Dinemark Limited | Professional & scientific | 2007 |
| Dingley Dell Limited | Manufacturing | 2018 |
| Direct Training Associates Limited | Information & communication | 1998 |
| Disabled NOT Dead Designs CIC | Manufacturing | 2026 |
| DIY Driver 0302 Ltd | Transport & logistics | 2025 |
| DJM Property Services Suffolk Ltd | Real estate | 2022 |
| DL UK Deals Ltd | Wholesale & retail | 2021 |
| DLF Property Investments Limited | Real estate | 2020 |
| DO Mortgages Limited | Financial services | 2006 |
| DOC Cotton Ltd | Manufacturing | 2017 |
| Doctor Golf Limited | Arts & recreation | 2000 |
| Dolphin Equity Ltd | Financial services | 2026 |
| Doozee Limited | Construction | 2010 |
| Dorey Financial Planning Limited | Financial services | 2014 |
| DOT Big Vault Ltd | Wholesale & retail | 2025 |
| Double E Properties Ltd | Real estate | 2021 |
| Douglas Inglis Consultancy Ltd | Agriculture & fishing | 2020 |
| Dove Design and Build Limited | Construction | 2019 |
| Downham Cottage Care Farm Ltd | Agriculture & fishing | 2011 |
| DR Margriet Health Ltd | Health & social care | 2024 |
| Drab. Ltd | Professional & scientific | 2003 |
| Dramatic Moments Ltd | Arts & recreation | 2008 |
| Dream Drains Ltd | Water & waste | 2017 |
| Driftwood Carpentry Ltd | Construction | 2026 |
| Drive Suffolk Ltd | Education | 2025 |
| Driveesmart Limited | Extraterritorial | 2019 |
| Drph Ltd | Construction | 2015 |
| Drury Trading Limited | Information & communication | 2022 |
| Drybridge Media Ltd | Administrative & support | 2016 |