| dampf.consulting GmbH | Hesse |
| Dampsoft Software Vertrieb GmbH | Schleswig-Holstein |
| Dan Electronic GmbH | |
| Dance GmbH | |
| Dandy Design | Lower Saxony |
| Danes Datennetzwerktechnik GmbH | Bavaria |
| Dango | |
| Daniel Homburg | North Rhine-Westphalia |
| Daniel's Xl Toolbox | Bavaria |
| daniel-IT | Hesse |
| Danner IT-Systemhaus GmbH | Baden-Württemberg |
| Danpower GmbH | |
| DANTE e.V. | Baden-Württemberg |
| DaPhi GmbH | Berlin |
| Darcblue AG | Hamburg |
| DarkNet | |
| Das Agenturhaus Werbe und Marketing GmbH | Bavaria |
| Das ASS | Hesse |
| DAS STUDIO Torsten Hegner GmbH | |
| Dasat UG | Bavaria |
| DASCOM Europe GmbH | Baden-Württemberg |
| Daseco GmbH | North Rhine-Westphalia |
| Dastani Consulting GmbH | Hesse |
| dasWeb.haus | Bavaria |
| Daswirdwas Design | Hesse |
| DATA 2000 GmbH | |
| Data Design System GmbH | North Rhine-Westphalia |
| Data Dienste | North Rhine-Westphalia |
| Data Display GmbH | Bavaria |
| Data Elektronik GmbH | |
| Data Insights GmbH | |
| Data Mart Consulting | |
| Data MATRIX Ltd | |
| Data Natives | |
| Data One GmbH | Saarland |
| Data Revenue GmbH | |
| Data Science Retreat | |
| data-inside GmbH | North Rhine-Westphalia |
| DATA-NG Consulting & Projects GmbH | |
| DATA-PLAN Computer Consulting GmbH | |
| data42 GmbH | |
| Dataasservices | |
| DATAbility GmbH | |
| Datablue GmbH | |
| Databoxes | Hamburg |
| Databyte GmbH | |
| DATAC Aktiengesellschaft | |
| DataCAD Software & Service GmbH | Rhineland-Palatinate |
| Datacake GmbH | |
| datacapo IT sports services GmbH | |