| Arvid Kahl | Saxony |
| ARX Landsysteme GmbH | |
| ARX Robotics GmbH | |
| Arxum GmbH | |
| ARYA-Computer GmbH | |
| ärzte.de MediService GmbH & Co. KG | |
| ärzte.de MediService GmbH & Co. KG | |
| AS Address Solutions GmbH | North Rhine-Westphalia |
| AS Computertraining | Bavaria |
| AS-Infodienste GmbH | North Rhine-Westphalia |
| AS-International Association e. V. | |
| AS-SYSTEME UB GmbH | |
| ASA Automation GmbH | |
| asap Software Consulting GmbH | North Rhine-Westphalia |
| ASBION Software GmbH | Baden-Württemberg |
| ASC Technologies AG | Bavaria |
| Ascanis oHG | Baden-Württemberg |
| Ascendro PRO GmbH | |
| Aschendorff NEXT GmbH & Co. KG | North Rhine-Westphalia |
| ASCI Systemhaus GmbH | Berlin |
| Ascolab GmbH | Bavaria |
| ASCOMP Software GmbH | Baden-Württemberg |
| Ascon Systems Holding GmbH | |
| Ascyrus Medical GmbH | |
| ASDIS Software AG | Berlin |
| Aseaco | Hesse |
| ASG Consult GmbH | |
| Asgoodasnew Electronics GmbH | |
| Ashampoo GmbH & Co. KG | Lower Saxony |
| Asi GmbH | Hesse |
| Asipto UG (haftungsbeschränkt) | Berlin |
| ASIS GmbH | Bavaria |
| ASK-Systems GmbH | |
| AskBrian | |
| ASKi & Data Intelligence GmbH | |
| ASKION GmbH | |
| Asklepios Kliniken GmbH & Co. KGaA | |
| Asknet AG | Baden-Württemberg |
| Askui GmbH | |
| ASL Angewandte Software-Lösungen GmbH | |
| ASM GmbH | Bavaria |
| ASNTECH GmbH | Baden-Württemberg |
| ASO GmbH | North Rhine-Westphalia |
| ASP-Equipment GmbH | |
| AspectC++ | North Rhine-Westphalia |
| ASS | Baden-Württemberg |
| ASS.TEC GmbH | Baden-Württemberg |
| Assay.Works GmbH | |
| ASSD GmbH | |
| Assecor Venture GmbH | |