| 6701 | SMCX | *STASO MILLING CO. | | | PWRC |
| 6702 | SMCX | *SIMMONS CO. | | | PWRC |
| 6703 | SMCX | *STANDARD MILLING CO. [ALTUS CO.] | | | PWRC |
| 6704 | SMCX | +SAN MIGUEL ELECTRIC COOPERATIVE, INC. | | | PWRC |
| 6705 | SMCX | San Miguel Electric Cooperative | | | RSRV |
| 6706 | SMCX | SAN MIGUEL ELECTRIC COOPERATIVE INC | | | SCAC4 |
| 6707 | SMCY | SUMME | | | SCAC4 |
| 6708 | SMCZ | (MEC) MAINE CENTRAL | | | PWRC |
| 6709 | SMCZ | Maine Central Railroad | | | RSRV |
| 6710 | SMD | Servicios Aereos la Marquesa, S.A. de C.V. | Callsign: Servicios Marquesa, | MEX | AVCODES |
| 6711 | SMD | SMJet S.r.l. | Callsign: Skymap, | RSM | AVCODES |
| 6712 | SMD | Servicios Aereos La Marquesa | | | ICAO1 |
| 6713 | SMD | *SHOWA LINE, LTD. | | | PWRC |
| 6714 | SMD | *STATE OF MARYLAND | | | PWRC |
| 6715 | SMD | SLEZSKOMORAVSKÁ DRÁHA a.s. | | CZ | VKM |
| 6716 | SMDA | SMD TRANSPORTATION MANAGEMENT INC | | | SCAC4 |
| 6717 | SMDD | SMITH, C R SMITH TRUCKING (DEDICATE | | | SCAC4 |
| 6718 | SMDG | SMITH, DENNIS TRUCKING | | | SCAC4 |
| 6719 | SMDH | S M D INC | | | SCAC4 |
| 6720 | SMDI | SMALL, DON & SONS OIL DISTRIBUTION | | | SCAC4 |
| 6721 | SMDM | S & M TRANSPORT LLC | | | SCAC4 |
| 6722 | SMDP | SLAWSON MANUFACTURING COMPANY INC | | | SCAC4 |
| 6723 | SMDS | S. M. D. S | | | SCAC1 |
| 6724 | SMDT | SCHMIDT AND SONS INC | | | SCAC4 |
| 6725 | SMDU | 3M COMPANY | | USA | BIC |
| 6726 | SMDU | MINNESOTA MINING AND MANUFACTURING - 3M COMPANY | | | PWRC |
| 6727 | SMDU | Minnesota Mining and Manufacturing (3M) | | | RSRV |
| 6728 | SMDU | 3M COMPANY | | | SCAC3 |
| 6729 | SMDU | SPECIALTY MATERIALS DIVISION 3M COM | | | SCAC4 |
| 6730 | SMDV | SUPERIOR MANUFACTURING DIVISION | | | SCAC4 |
| 6731 | SME | Semos | Callsign: Semich, | KZ | AVCODES |
| 6732 | SME | Smart Aviation Company | IATA: M4, Callsign: Smart Aviation, Designator M4 recalled by IATA | ET | AVCODES |
| 6733 | SME | Smart Aviation Company | Callsign: Smart Aviation, Designator M4 recalled by IATA | ET | AVCODES |
| 6734 | SME | Semos | | | ICAO1 |
| 6735 | SMEA | SCRAP METAL PROCESSORS INC. | | | SCAC1 |
| 6736 | SMEA | SCRAP METAL PROCESSORS INC | | | SCAC4 |
| 6737 | SMED | Santander - Mediterrano | | E | TRAFFIC |
| 6738 | SMEG | SMITH, E G INC | | | SCAC4 |
| 6739 | SMEH | STRATTON METALS LLC | | | SCAC4 |
| 6740 | SMEJ | STERLING MARITIME LTD OF MARSHALL I | | | SCAC4 |
| 6741 | SMEK | SHOW ME TRUCKING | | | SCAC4 |
| 6742 | SMEL | SOMERSET LLC | | | SCAC4 |
| 6743 | SMEP | SONSHINEM | | | SCAC4 |
| 6744 | SMEQ | SUPREM | | | SCAC4 |
| 6745 | SMER | SEA MERCHANTS LINE INC | | | SCAC4 |
| 6746 | SMET | SAS TRUCKS LLC | | | SCAC4 |
| 6747 | SMEU | SMET BUILDING PRODUCTS LIMITED | | GB | BIC |
| 6748 | SMEV | STAMEY CATTLE COMPANY LLP | | | SCAC4 |
| 6749 | SMEW | SAMRA TRUCKING | | | SCAC4 |
| 6750 | SMEX | South Mississippi Electric Power Association | added 1/1978; 1/1980-7/2005 | | NAKINA |
| 6751 | SMEX | South Mississippi Electric Power Association | added 1/78; 1/80-7/2000 | | NRHS |
| 6752 | SMEX | SOUTH MISSISSIPPI ELECTRIC POWER ASSOCIATION | | | PWRC |
| 6753 | SMEX | South Mississippi Electric Power Association | | | RSRV |
| 6754 | SMEX | SOUTH MISSISSIPPI ELECTRIC POWER AS | | | SCAC4 |
| 6755 | SMEY | SMOKEY MOUNTAIN EXPRESS | | | SCAC4 |
| 6756 | SMEZ | SUPERIOR MIDWEST ENERGY | | | PWRC |
| 6757 | SMF | Smalandsflyg AB | Callsign: Gordon, | S | AVCODES |
| 6758 | SMF | San Marino Executive Aviation S.r.l. | Callsign: Smea, ICAO Callsign changed to Seres. | RSM | AVCODES |
| 6759 | SMF | San Marino Executive Aviation S.r.l. | Callsign: Seres, ICAO Callsign changed from Smea. | RSM | AVCODES |
| 6760 | SMF | Smalandsflyg | | | ICAO1 |
| 6761 | SMFA | SOUTHMAN ALFALFA PRODUCERS LTD | | | SCAC4 |
| 6762 | SMFB | SAM LOGISTICA II | | | SCAC4 |
| 6763 | SMFC | SMS TRANSPORT LLC | | | SCAC4 |
| 6764 | SMFD | SOLIS MEXICAN FOODS INC | | | SCAC4 |
| 6765 | SMFF | SMF INC | | | SCAC4 |
| 6766 | SMFH | S M FREIGHT INC | | | SCAC4 |
| 6767 | SMFI | SPARTAN MOTOR FREIGHT INC | | | SCAC4 |
| 6768 | SMFJ | STELLA MARINE SERVICES GMBH & CO KG | | | SCAC4 |
| 6769 | SMFM | STEARLYS MOTOR FREIGHT INC | | | SCAC4 |
| 6770 | SMFN | SEARANGE MANAGEMENT INC | | | SCAC4 |
| 6771 | SMFP | S M FINE ART APPRAISALS | | | SCAC4 |
| 6772 | SMFQ | SHUMAN SPECIALIZED TRANSPORTATION L | | | SCAC4 |
| 6773 | SMFV | SENTRY MOTOR FREIGHT INC | | | SCAC4 |
| 6774 | SMFY | SMEAD MANUFACTURING COMPANY | | | SCAC4 |
| 6775 | SMG | RAF St. Mawgan Search And Rescue | | GB | AVCODES |
| 6776 | SMG | Smartline Luftfahrt GmbH | Callsign: Smartline, | A | AVCODES |
| 6777 | SMG | RAF St Mawgan Search and Rescue | | | ICAO1 |
| 6778 | SMG | Sersa Maschineller Gleisbau AG | | CH | VKM |
| 6779 | SMGC | SAMCO TECHNOLOGIES INC | | | SCAC4 |
| 6780 | SMGD | SMITH, A TRUCKING INC | | | SCAC4 |
| 6781 | SMGG | SMART MANAGEMENT GROUP INC | | | SCAC4 |
| 6782 | SMGI | SMEDEMA TRUCKING INC | | | SCAC4 |
| 6783 | SMGN | SEA MASTER LEGEN SA PANAMA | | | SCAC4 |
| 6784 | SMGP | SILVER MAPLE GAMEBIRDS | | | SCAC4 |
| 6785 | SMGQ | SMG | | | SCAC4 |
| 6786 | SMGS | ST MARTIN OIL AND GAS INC | | | SCAC4 |
| 6787 | SMGT | SMITH, GEORGE TRUCKING CO | | | SCAC4 |
| 6788 | SMGU | LIMITED LIABILITY PARTNERSHIP SMARTLOG | | KZ | BIC |
| 6789 | SMGV | S M G LOGISTICS INC | | | SCAC4 |
| 6790 | SMGX | SIMS GROUP USA CORP. | | | PWRC |
| 6791 | SMGX | SIMS GROUP USA CORPORATION | | | SCAC4 |
| 6792 | SMH | Smithair, Inc. | Callsign: Smithair, | USA | AVCODES |
| 6793 | SMH | Smithair | | | ICAO1 |
| 6794 | SMHC | SABRE MACHINE TOOL INC | | | SCAC4 |
| 6795 | SMHF | SMITH TRANSFER COMPANY INC | | | SCAC4 |
| 6796 | SMHG | SMITH, GREG C | | | SCAC4 |
| 6797 | SMHM | SAINT MICHAEL SHIPPING COMPANY LIMI | | | SCAC4 |
| 6798 | SMHO | SMITH & CO | | | SCAC4 |
| 6799 | SMHQ | SMITH TRUCKING | | | SCAC4 |
| 6800 | SMHS | SAINT MICHAELS EQUIPMENT INC | | | SCAC4 |
