| 1 | IAN | Compania Interandina de Aviacion | Callsign: Interandes, | CO | AVCODES |
| 2 | IAN | Inter Aviation | Callsign: Interav, | RO | AVCODES |
| 3 | IAN | Ibom Airlines Limited | IATA: QI, Callsign: Ibom, | WAN | AVCODES |
| 4 | IANI | IAN INTERNATIONAL INC | | | SCAC4 |
| 5 | IANR | Iowa Northern Ry. | added 1/1982; 1/1994-7/2005 | | NAKINA |
| 6 | IANR | Iowa Northern Ry. | added 1/82; 1/94-7/2000 | | NRHS |
| 7 | IANR | IOWA NORTHERN RAILWAY CO. | | | PWRC |
| 8 | IANR | Iowa Northern Railway | | | RSRV |
| 9 | IANR | Iowa Northern Railway Co. | | USA | TRAFFIC |
| 10 | IANW | Iowa Northwestern R.R. | added 7/2003; 7/2005; eliminated 7/2005 | | NAKINA |
| 11 | IANW | IOWA NORTHWESTERN RAILROAD | | | PWRC |
| 12 | IANW | IOWA NORTHWESTERN RAILROAD | | | SCAC4 |
