| 1 | MCO | Aerolineas Marcos, S.A. de C.V. | Callsign: Marcos, | MEX | AVCODES |
| 2 | MCO | Aerolineas Marcos | | | ICAO1 |
| 3 | MCOA | MCGEE CORPORATION | | | SCAC4 |
| 4 | MCOD | MCLEOD, MIKE TRUCKING | | | SCAC4 |
| 5 | MCOF | MARCOTTE, PAUL FARMS INC | | | SCAC4 |
| 6 | MCOG | MCO FREIGHT CONNECTION INC | | | SCAC4 |
| 7 | MCOI | MORRIS COMMERCIAL ENTERPRISES INC | | | SCAC4 |
| 8 | MCOK | MCCORMICK & SONS TRANSPORT | | | SCAC4 |
| 9 | MCOL | MILLER COLONY INC | | | SCAC4 |
| 10 | MCOM | McCOMBS FREIGHT LINE, INC | | | SCAC1 |
| 11 | MCON | MARLINS CONSOLIDATORS INC | | | SCAC4 |
| 12 | MCOO | MACON OIL CO | | | SCAC4 |
| 13 | MCOT | MATCO TRANSPORTATION, INC | | | SCAC1 |
| 14 | MCOU | 4SEAS SHIPPING AND FORWARDING BV | | NL | BIC |
| 15 | MCOV | MACOM INCORPORATED | | | SCAC4 |
| 16 | MCOW | MARYLAND CHEMICAL COMPANY | | | SCAC4 |
