| 1 | SIF | Skycy Freighters International Ltd. | Callsign: Skycy, | EAK | AVCODES |
| 2 | SIF | AirSial Limited | IATA: PF, Callsign: Air Sial, | PK | AVCODES |
| 3 | SIF | Società Italiana per le Imprese Pubbliche e Ferrovie | 1927-1956 | I | TRAFFIC |
| 4 | SIFA | SIFANDROS CARRIER LTD | | | SCAC4 |
| 5 | SIFD | SIRIUS INTERNATIONAL FREIGHT FORWAR | | | SCAC4 |
| 6 | SIFE | SUPERIOR INTERNATIONAL FREIGHT FORW | | | SCAC4 |
| 7 | SIFF | SCHENKER INC | | | SCAC4 |
| 8 | SIFI | SILFIES, F T INC | | | SCAC4 |
| 9 | SIFM | SIL LLC | | | SCAC4 |
| 10 | SIFO | SIFNOS TANKER CORPORATION | | | SCAC4 |
| 11 | SIFP | STEELTECH INDUSTRIAL FABRICATION IN | | | SCAC4 |
| 12 | SIFQ | STAR ICE & FUEL INC | | | SCAC4 |
| 13 | SIFS | SIMONSON FREIGHT SERVICE | | | SCAC1 |
| 14 | SIFT | Societá Italiana Ferrovie e Tranvie | | I | TRAFFIC |
| 15 | SIFU | NEWPORT EUROPE B.V. | | NL | BIC |
| 16 | SIFX | SIEMENS FINANCIAL SERVICES | | | SCAC4 |
