| Navn | Postnummer | By |
|---|---|---|
| Carl J Nielsen A/S | 8930 | Randers NØ |
| Carlo Gavazzi Handel A/S | 8370 | Hadsten |
| Carsten Holm A/S | 5750 | Ringe |
| Check-line ApS | 6760 | Ribe |
| CIMCO A/S | 2100 | København Ø |
| Cleansafe A/S | 5260 | Odense S |
| Columbus A/S | 2750 | Ballerup |
| Combitherm A/S | 8653 | Them |
| ComSystem A/S | 3490 | Kvistgård |
| Condair A/S | 8680 | Ry |
| Constructor Danmark A/S | 4320 | Lejre |
| Copenhagen Pump | 2650 | Hvidovre |
| Coreline A/S | 7000 | Fredericia |
| CP ApS | 4130 | Viby Sjælland |
| CPF Denmark A/S | 6800 | Varde |