| COM4 Automatisering | North Brabant |
| coMakeIT B.V. | Utrecht |
| Combined Computer Services B.V. | Utrecht |
| ComCare ICT | North Holland |
| ComControl | North Holland |
| Comercia | Gelderland |
| comfort-ia.nl | South Holland |
| Comm.On | |
| Commit-IT B.V. | South Holland |
| Communicatiehaven | |
| Communics Communicatie | |
| Companet | Overijssel |
| Companial | Utrecht |
| Compano Online Software | Friesland |
| Competence Factory | North Holland |
| Complement Pharma | North Holland |
| Complet Automatisering | Limburg |
| Complies B.V. | Drenthe |
| Compose Network Connections B.V. | North Brabant |
| Composita | Groningen |
| Compra B.V. | South Holland |
| Compram Systeemhuis B.V. | North Brabant |
| Compri ICT | Drenthe |
| Compu Act Opleidingen | North Holland |
| Compubase | North Brabant |
| Compudac Solutions B.V. | Gelderland |
| Compules | South Holland |
| Compusat | North Brabant |
| Computable.nl | North Holland |
| Computel | Gelderland |
| Computerhulp bij u thuis | North Holland |
| Computerservice Assen | Drenthe |
| Computerstunt.nl | North Holland |
| Computersupport Apeldoorn | |
| ComputerZorg | South Holland |
| Computest | |
| Computrain | North Holland |
| Comsol | South Holland |
| Comsolve | Gelderland |
| Comsult N.V. | Groningen |
| Conclusion | Utrecht |
| Conference Compass | South Holland |
| Conk | North Brabant |
| Connec2 B.V. | |
| Connecterra B.V. | |
| Conniction | Gelderland |
| ConsolePro | North Brabant |
| Consolit | South Holland |
| Consorto B.V. | |
| Conspect Consulting & ICT | Flevoland |