| Comlabs Informatik GmbH | Basel-Landschaft |
| compart Engineering AG | Bern |
| Compass IT AG | Basel-Stadt |
| comperio.ch AG | Bern |
| Comphya S.A. | |
| Compnet | Zurich |
| Compona AG | Zurich |
| CompPair Technologies Ltd | |
| Compu-Trade GmbH | Bern |
| Computer Controls AG | Zurich |
| Computer Rock | |
| Computer Software und Netzwerke AG | Basel-Stadt |
| Computer-Point | Zurich |
| Computerfuchs AG | Bern |
| Computerline GmbH | Lucerne |
| Computerworld.ch | Zurich |
| Comrec GmbH | Bern |
| Comsol | Zurich |
| Comsolit AG | Thurgau |
| Comsolutions Kommunikations - Lösungen GmbH | Schwyz |
| Comvation AG | Bern |
| Comworld GmbH | Schwyz |
| Concept Mag S.à.r.l. | Valais |
| Concepto | Vaud |
| Concetweb | Fribourg |
| Concordium | |
| Confecta AG | Thurgau |
| Connect 2 Communications GmbH | Lucerne |
| Connect-i S.à.r.l. | Vaud |
| Connect44 | Lucerne |
| Connectcom Networks S.A. | Vaud |
| Conrad Electronic S.A. | Schwyz |
| Conrad Engineering | Aargau |
| Conseils et Développements Informatiques S.A. | Fribourg |
| Consensus Informatik AG | Basel-Landschaft |
| Consultinform AG | Zurich |
| Container Registry | |
| Contao | |
| Contaxe AG | Schaffhausen |
| Contech Electronic AG | Zurich |
| Contentserv Swiss GmbH | |
| Contovista AG | |
| Contreforme S.à.r.l. | Neuchâtel |
| Contrinex AG | Fribourg |
| Coople | |
| COP Informatik AG | St. Gallen |
| Copper | |
| CORE Association | Geneva |
| Coresystems AG | Aargau |
| Corintis | |