| aedifion GmbH | |
| AEMtec GmbH | Berlin |
| aenia International GmbH & Co. KG | Baden-Württemberg |
| AENU Advisor GmbH | |
| Aeotec Group GmbH | |
| Aequitas Software GmbH & Co. KG | |
| AERAsec | Bavaria |
| Aerosoft GmbH | North Rhine-Westphalia |
| AeroSys | |
| Aervideo GmbH | |
| Aerzener Maschinenfabrik GmbH | |
| Aescuvest GmbH | |
| Aesir Interactive GmbH | |
| Aesku.Group GmbH | |
| Aeterna Electronic GmbH | Bavaria |
| Aetka Communication Center AG | Saxony |
| aevum GmbH | Bavaria |
| Aextra Software | Lower Saxony |
| AF Data Systems GmbH | |
| AF Inventions GmbH | Lower Saxony |
| AF Unternehmensberatungs- und Beteiligungs GmbH | North Rhine-Westphalia |
| AFAP-AVA | North Rhine-Westphalia |
| afb Application Services AG | Bavaria |
| Affilix Ltd | Lower Saxony |
| Affimed GmbH | |
| AFG Ausführungsgesellschaft für Gebäudetechnik mbH | |
| AFI GmbH | Baden-Württemberg |
| Afp-Technologie | Lower Saxony |
| AFS-Software GmbH & Co. KG | Hesse |
| AFT Microwave GmbH | Baden-Württemberg |
| AFTS GmbH | |
| Agando | Lower Saxony |
| Agenda Informationssysteme GmbH & Co. KG | Bavaria |
| Agendis Business Center Stuttgart | |
| Agens Consulting GmbH | Bavaria |
| AGENT++ | |
| agentbase AG | |
| Agentes AG | Bavaria |
| Agentscape AG | Berlin |
| Agentur Bonk | Hesse |
| agentur elf42 | Lower Saxony |
| Agentur Karl & Karl | Schleswig-Holstein |
| Agentur sehpunkt, Petzold, Pfäffle & Partner GbR | Baden-Württemberg |
| Agentur zur schönen Gärtnerin GmbH | Bavaria |
| AgenturWebfox GmbH | Berlin |
| agex IT GmbH | |
| AGFEO GmbH & Co. KG | North Rhine-Westphalia |
| Agil Software GmbH | Baden-Württemberg |
| Agile Partners GmbH | |
| Agile Robots AG | Bavaria |