| 1 | SMC | Sabang Merauke Raya Air Charter PT. | Callsign: Samer, Name changed to SMAC (Sabang Merauke Raya Air Charter), PT. | RI | AVCODES |
| 2 | SMC | SMAC (Sabang Merauke Raya Air Charter), PT. | Callsign: Samer, Name changed from Sabang Merauke Raya Air Charter PT. | RI | AVCODES |
| 3 | SMC | Comlux San Marino S.r.l. | Callsign: Comlux, | RSM | AVCODES |
| 4 | SMC | Sabang Merauke Raya Air Charter | | | ICAO1 |
| 5 | SMC | A. E. STALEY MANUFACTURING CO. | | | PWRC |
| 6 | SMC | Chemin de Fer & Autobus Sierre-Montana-Crans | | CH | TRAFFIC |
| 7 | SMCD | SEAMATES CONSOLIDATION SERVICE INC | | | SCAC4 |
| 8 | SMCE | SKYLINE MAIL CARRIERS INC | | | SCAC4 |
| 9 | SMCF | SMITH CARTAGE INC | | | SCAC4 |
| 10 | SMCF | Sercice Militaire des Chemines de Fer | | FR | VKM |
| 11 | SMCI | SPECIAL MACHINING CO INC | | | SCAC4 |
| 12 | SMCJ | SUMMERFORD TRUCK LINE INC | | | SCAC4 |
| 13 | SMCL | SMITH, C. L., TRUCKING | | | SCAC1 |
| 14 | SMCN | SAMS TRUCKING | | | SCAC4 |
| 15 | SMCO | SAN MARCOS TRANSFER | | | SCAC4 |
| 16 | SMCO | S.M.Coaches | | GB | TRAFFIC |
| 17 | SMCP | SECO MANUFACTURING COMPANY INC | | | SCAC4 |
| 18 | SMCQ | SMITH, W., CARTAGE COMPANY, INC | | | SCAC1 |
| 19 | SMCQ | SMITH, W CARTAGE COMPANY INC | | | SCAC4 |
| 20 | SMCT | SMITH, C R TRUCKING | | | SCAC4 |
| 21 | SMCU | SM CONTAINER LINES | | ROK | BIC |
| 22 | SMCU | ASTRIUM GMBH | | | SCAC4 |
| 23 | SMCV | SAN MARCOS GROUP LLC | | | SCAC4 |
| 24 | SMCX | Staso Milling Co. | 7/1930-7/1932 | | NAKINA |
| 25 | SMCX | The Simmons Co. | 1/1943-1/1946 | | NAKINA |
| 26 | SMCX | The Altus Co. | added 1/1962; eliminated 1/1963 | | NAKINA |
| 27 | SMCX | Standard Milling Co. | added 1/1963; 7/1965-4/1970; eliminated 4/1972 | | NAKINA |
| 28 | SMCX | San Miguel Electric Cooperative, Inc. | added 10/1981; 1/1994-7/2005 | | NAKINA |
| 29 | SMCX | The Altus Co. | added 1/62 | | NRHS |
| 30 | SMCX | Standard Milling Co. | 7/65-4/70; eliminated 4/72 | | NRHS |
| 31 | SMCX | San Miguel Electric Cooperative, Inc. | added 10/81; 1/94-7/2000 | | NRHS |
| 32 | SMCX | *STASO MILLING CO. | | | PWRC |
| 33 | SMCX | *SIMMONS CO. | | | PWRC |
| 34 | SMCX | *STANDARD MILLING CO. [ALTUS CO.] | | | PWRC |
| 35 | SMCX | +SAN MIGUEL ELECTRIC COOPERATIVE, INC. | | | PWRC |
| 36 | SMCX | San Miguel Electric Cooperative | | | RSRV |
| 37 | SMCX | SAN MIGUEL ELECTRIC COOPERATIVE INC | | | SCAC4 |
| 38 | SMCY | SUMME | | | SCAC4 |
| 39 | SMCZ | (MEC) MAINE CENTRAL | | | PWRC |
| 40 | SMCZ | Maine Central Railroad | | | RSRV |
