| Navn | Postnummer | By |
|---|---|---|
| Marineshaft A/S | 9850 | Hirtshals |
| MARPRO Group | 3000 | Helsingør |
| Marstal Navigationsskole | 5960 | Marstal |
| MARTEC | 9900 | Frederikshavn |
| MARTEC | 9900 | Frederikshavn |
| ME Production A/S | 9900 | Frederikshavn |
| Megatrade | 2650 | Hvidovre |
| Mirit Glas A/S | 2730 | Herlev |
| MODU Valves A/S | 7100 | Vejle |
| MOL Chemical Tankers Europe A/S | 2900 | Hellerup |