| GSD Software Design GmbH | Hamburg |
| GSG Global Service Group GmbH | |
| GSI Helmholtzzentrum für Schwerionenforschung GmbH | |
| GSMB Agency GmbH | |
| GT-EDV | Saxony |
| GTC TeleCommunication GmbH | Baden-Württemberg |
| GTE Industrieelektronik GmbH | North Rhine-Westphalia |
| GTR Global Technology Remarketing and Recycling GmbH | Bavaria |
| GTRON Industrieelektronik GmbH | North Rhine-Westphalia |
| GTS Computer GmbH | Baden-Württemberg |
| GTS Systems and Consulting GmbH | |
| Guardus Solutions AG | Baden-Württemberg |
| Guddat & Müller GbR | Bavaria |
| GUIDED Development Heidelberg GmbH | |
| Gunter Avenius | Bavaria |
| Guntermann & Drunck GmbH | North Rhine-Westphalia |
| Günther Pexa | Bavaria |
| Gunzilla Games | |
| Gurado GmbH | |
| Gurkcity Webdesign | Hesse |
| Gurock | Hesse |
| Gursky Design | Baden-Württemberg |
| GUS Group AG & Co. KG | North Rhine-Westphalia |
| Güssow GmbH | Hamburg |
| Gutschein-Spezialist | |
| GuxDu.com | North Rhine-Westphalia |
| GW Leiterplatten Dresden GmbH & Co. KG | Saxony |
| GWJ Technology GmbH | Lower Saxony |
| GWS Gesellschaft für Warenwirtschafts-Systeme mbH | North Rhine-Westphalia |
| GWX | Hesse |
| GXS-Media Gier Seilberger GbR | Baden-Württemberg |
| Gymondo GmbH | |
| Gypsilon Software GmbH | North Rhine-Westphalia |
| gz[media] GbR | |
| H & R Netzwerk | North Rhine-Westphalia |
| H&L Software GmbH | |
| H&M System Software GmbH | Hesse |
| H&P Infomedia GmbH | North Rhine-Westphalia |
| H+H Software GmbH | Lower Saxony |
| H-Soft – TMB GmbH | Baden-Württemberg |
| H. Adam GmbH | Bavaria |
| H.+H. Priessnitz K.J.Sack GbR | Bavaria |
| h.com networkers GmbH | North Rhine-Westphalia |
| H.E.I. Informationssysteme GmbH | Baden-Württemberg |
| H.E.R.T.Z Elektronik GmbH | Brandenburg |
| H2D2 GmbH | Berlin |
| HAAGE & PARTNER Computer GmbH | Hesse |
| HABA Sales GmbH & Co. KG | |
| Habemus! Electronic + Transfer GmbH | Bavaria |
| Haberer Electronic GmbH | Baden-Württemberg |