| adKOMM Software GmbH | Bavaria |
| ADLON Intelligent Solutions GmbH | Baden-Württemberg |
| ADM Electronic GmbH | Bavaria |
| ADMAX Werbeagentur GmbH | North Rhine-Westphalia |
| Admetrics GmbH | |
| Admidio | North Rhine-Westphalia |
| adminForge | North Rhine-Westphalia |
| Administration Intelligence AG | Bavaria |
| AdmiralCloud AG | |
| Admitad GmbH | Baden-Württemberg |
| ADMOVI GmbH | Brandenburg |
| ADN – Advanced Digital Network GmbH | |
| Adojo GmbH | Bavaria |
| Adolf Würth GmbH & Co. KG | |
| ADONTEC Computer Systems GmbH | Baden-Württemberg |
| Adoo UG (haftungsbeschränkt) | |
| Adragos Pharma GmbH | |
| Adrenomed AG | |
| Adrodev GmbH | Baden-Württemberg |
| AdShield | |
| Adsolem GmbH | Saxony |
| Adspert | Berlin |
| ADTELLIGENCE GmbH | Baden-Württemberg |
| adtraffic GmbH | Bavaria |
| Adtriba GmbH | |
| ADUK GmbH | |
| AdUp Technology | |
| ADVA | Bavaria |
| AdvanceCOR GmbH | |
| Advanced Applications GmbH | Baden-Württemberg |
| Advanced Blockchain AG | |
| Advanced IT Security Solutions GmbH | |
| Advanced Realtime Tracking GmbH | Bavaria |
| Advanced Software GmbH | |
| Advanced Temperature Test Systems GmbH | |
| Advanced UniByte GmbH | Baden-Württemberg |
| Advancis Software & Services GmbH | Hesse |
| Advantage Software Consulting GmbH | Berlin |
| Advantic GmbH | Schleswig-Holstein |
| Advantic Systemhaus GmbH | Saxony-Anhalt |
| ADVARIS Informationssysteme GmbH | Baden-Württemberg |
| ADventas Consulting | Hamburg |
| Adventos GmbH | Hamburg |
| advICo mircroelectronics GmbH | North Rhine-Westphalia |
| Adviion GmbH | Baden-Württemberg |
| AdVision digital GmbH | |
| AdvoCoder UG (haftungsbeschränkt) | Hamburg |
| AEB SE | |
| AED SICAD Aktiengesellschaft | North Rhine-Westphalia |
| Aed-sicad AG | North Rhine-Westphalia |