| typolink.org TYPO3 Webkatalog | Baden-Württemberg |
| Typolog Software Ltd. & Co KG | Schleswig-Holstein |
| TZ-Elektronik | Lower Saxony |
| U+P Systemhaus GmbH | North Rhine-Westphalia |
| U.I. Lapp GmbH | Baden-Württemberg |
| U.T.E. Electronic GmbH & Co. KG | North Rhine-Westphalia |
| UB-Soft | Lower Saxony |
| UB-Software Entwicklungs- und Vertriebs- GmbH | Baden-Württemberg |
| UBeCO GmbH | Bavaria |
| Uberall GmbH | Berlin |
| Uberchord UG (haftungsbeschränkt) | |
| Überlandwerk Groß-Gerau GmbH | Hesse |
| Ubermetrics Technologies GmbH & Co. KG | |
| UBERTAGE Bürogemeinschaft | |
| UBF EDV Handel und Beratung | Bavaria |
| UBH Software & Engineering GmbH | |
| Ubilabs GmbH | |
| UBK GmbH | Bavaria |
| UBM Drecker GmbH | Schleswig-Holstein |
| Ubuntu Privacy Remix | North Rhine-Westphalia |
| Ubuntuusers | Lower Saxony |
| UC Umwelt Consulting GmbH | Saarland |
| uCastMe GmbH | |
| UCI Software GmbH | Baden-Württemberg |
| UD Media GmbH | North Rhine-Westphalia |
| UDIT GmbH | Rhineland-Palatinate |
| Ueberbit GmbH | Baden-Württemberg |
| Uedelhoven GmbH & Co. KG | |
| Ueffing.net | North Rhine-Westphalia |
| UGR Computer Service | North Rhine-Westphalia |
| UHDE Datentechnik GmbH | Rhineland-Palatinate |
| UHER informatik GmbH | Lower Saxony |
| UHP Software | Hesse |
| UIMC Dr. Vossbein GmbH & Co. KG | North Rhine-Westphalia |
| UL Method Park GmbH | Bavaria |
| ULC Business Solutions GmbH | Saxony |
| ulf-theis.de | Saarland |
| Uli Ludwig | Hesse |
| Ullrich iT Systeme | North Rhine-Westphalia |
| Ulmer Akademie für Datenschutz und IT-Sicherheit | Baden-Württemberg |
| Ulmer-Kemo GmbH & Co. KG | Baden-Württemberg |
| Ulrich Doerge | Berlin |
| Ulrich Quadt GmbH | Hamburg |
| Ulrich Richter GmbH | North Rhine-Westphalia |
| Ulrike Stehling | North Rhine-Westphalia |
| UltiHash GmbH | |
| Ultimate | |
| ultimate.ai | Berlin |
| Ultra Consulting Network GmbH | North Rhine-Westphalia |
| Ultra Tendency | |