| TMT GmbH & Co. KG | Bavaria |
| TNG Technology Consulting GmbH | Bavaria |
| TNM Software GmbH | Saarland |
| to-teach.ai | |
| TOA Electronics Europe GmbH | Hamburg |
| TOA Festival | |
| TOASTER Internet UG(haftungsbeschränkt) & Co. KG | North Rhine-Westphalia |
| Tobax Software GmbH | North Rhine-Westphalia |
| Tobias Hüllmandel Softwareentwicklung | Baden-Württemberg |
| Tobias Krähling | North Rhine-Westphalia |
| Tobias Kühn | Bavaria |
| Tobias Ulm | Bavaria |
| Tobit.Software | North Rhine-Westphalia |
| TodaySystems GmbH | |
| todo GmbH | Berlin |
| tog.is information design | Bavaria |
| Tokenize.it | |
| tokenstreet GmbH | |
| Tolerant Software | |
| TolerogenixX GmbH | |
| Tolingo GmbH | |
| Tomcom GmbH | Bavaria |
| Tomorrow GmbH | |
| Tomorrow University of Applied Sciences | Berlin |
| TOMTEC Imaging Systems GmbH | Bavaria |
| TonerPartner GmbH | North Rhine-Westphalia |
| Tonfunk Elektronik Systeme GmbH | Saxony-Anhalt |
| toolbox Software GmbH | North Rhine-Westphalia |
| Tools of Innovators GmbH | |
| ToolStage Software Engineering | Hesse |
| Top 21 Systemhaus GmbH | |
| top itservices AG | Bavaria |
| TOP TEN Computervertrieb GmbH | Bavaria |
| Top-Platzierung | Baden-Württemberg |
| Top-Print Electronic GmbH | Bavaria |
| top.media GmbH | |
| TOP500 Supercomputers | Baden-Württemberg |
| Topas Therapeutics GmbH | |
| Topcom Kommunikationssysteme GmbH | North Rhine-Westphalia |
| Topi GmbH | |
| TopM Software GmbH | Bavaria |
| TOPO graphics Geoinformationssysteme GmbH | North Rhine-Westphalia |
| Topobyte | |
| Topobyte | |
| Topopt GmbH & Co. KG | Bavaria |
| TOPOS Personalberatung GmbH | |
| tops.net GmbH & Co. KG | Hesse |
| TOPTICA Photonics AG | Bavaria |
| Toptranslation GmbH | |
| TopWare Interactve | Baden-Württemberg |