| Holoplot GmbH | |
| Holoride | |
| Holstein Computer Gebhard & Erf GmbH | Schleswig-Holstein |
| Holsterlabs Digital Solutions | |
| höltl Retail Solutions GmbH | Hesse |
| Holy Technologies GmbH | |
| HolyHat | Schleswig-Holstein |
| holzapple.de - IT-Service für Apple-Systeme | Berlin |
| Homeday GmbH | |
| HOMEINFO Digitale Informationssysteme GmbH | Lower Saxony |
| Homepage Helden GmbH | Hamburg |
| Homepage-Diesnt | North Rhine-Westphalia |
| Homepage-nach-Preis.de | Bavaria |
| Homepage.eu | Saxony |
| Homepageservice4you | Baden-Württemberg |
| Honeypot GmbH | Berlin |
| Hoods GmbH | |
| hopf Elektronik GmbH | North Rhine-Westphalia |
| Hopkins GmbH | |
| HOPLIT - Business IT | Lower Saxony |
| Hopper Mobility | |
| Hör GmbH & Co. KG | Berlin |
| HoR House of Research GmbH | |
| Horak.net | Hesse |
| Hörburger AG | Bavaria |
| Horizon Teleports GmbH | |
| HORIZONT Software GmbH | |
| Hörmann GmbH | Bavaria |
| Horn & Görwitz GmbH & Co. KG | Berlin |
| HORN GmbH | Baden-Württemberg |
| Hornetsecurity GmbH | Lower Saxony |
| HorseAnalytics | |
| Horst Klaes GmbH & Co. KG | Rhineland-Palatinate |
| Horus-Net GmbH & Co. KG | Rhineland-Palatinate |
| Hospitality Digital GmbH | North Rhine-Westphalia |
| Host Europe GmbH | North Rhine-Westphalia |
| Host1 | North Rhine-Westphalia |
| Hosting-Rhein-Neckar | Baden-Württemberg |
| hosting.de GmbH | North Rhine-Westphalia |
| HOSTINGPLUS | Bavaria |
| HostingTime UG (haftungsbeschränkt) | Baden-Württemberg |
| hostix GmbH | |
| hostNET Medien GmbH | Bremen |
| HostPlace Internet-Dienstleistungen Leibenger & Müller GbR | North Rhine-Westphalia |
| Hostserver GmbH | Hesse |
| Hostsharing eG | Hamburg |
| Hostsystems GmbH | Bavaria |
| HOSTtest | |
| Hostway Deutschland GmbH | Lower Saxony |
| Hostweb GmbH | Hesse |