| 1 | INT | Intair, Inc. | Callsign: Intairco, | CDN | AVCODES |
| 2 | INT | Interstate Airlines, Inc. | Callsign: Inter-flight, | USA | AVCODES |
| 3 | INT | Integra Map & Geoinfomormacion Consulting, S.L. | Callsign: Integra, | E | AVCODES |
| 4 | INT | Intair | | | ICAO1 |
| 5 | INT | Norfolk Southern Ry. Co. (Norfolk Southern) | added 1/1991; 1/1994-7/2005 | | NAKINA |
| 6 | INT | Southern Ry. System | eliminated 1/1991 | | NAKINA |
| 7 | INT | Interstate R.R. | 8/1920-10/1966 & 1/1975-1/1980 | | NAKINA |
| 8 | INT | Interstate R.R. | 4/38-10/66 & 1/75-1/80 | | NRHS |
| 9 | INT | Southern Ry. System | eliminated 1/91 | | NRHS |
| 10 | INT | Norfolk Southern Ry. Co. | added 1/91; 1/94-7/2000 | | NRHS |
| 11 | INT | NORFOLK SOUTHERN [SOUTHERN; INTERSTATE RAILROAD] | | | PWRC |
| 12 | INT | Interstate Railroad (Norfolk Southern) | | | RSRV |
| 13 | INT | INTERSTATE RAILROAD COMPANY (RAILRO | | | SCAC4 |
| 14 | INT | Interstate Railroad | | USA | TRAFFIC |
| 15 | INT | ČSKD - INTRANS a.s. | | CZ | VKM |
| 16 | INTA | INTRANSIT | | | SCAC4 |
| 17 | INTB | INTERNATIONAL MOTORCYCLE BROKERS IN | | | SCAC4 |
| 18 | INTBA | Intertop-Bau GmbH | | DE | VKM |
| 19 | INTC | INTERTRANS INTERNATIONAL TRANSPORT | | | SCAC4 |
| 20 | INTD | INTERSTATE DISTRIBUTOR CO | | | SCAC1 |
| 21 | INTD | INTERSTATE DISTRIBUTOR CO | | | SCAC4 |
| 22 | INTE | INTERPORT LINES | | | SCAC4 |
| 23 | INTEG | IntEgro Verkehr GmbH | | DE | VKM |
| 24 | IntEgro | IntEgro Verkehr GmbH | Reichenbach | D | privat-bahn.de |
| 25 | INTER | Interkom EOOD | | BG | TRAFFIC |
| 26 | INTERNATIONAL | TRANSBORDE | | | SCAC4 |
| 27 | INTF | INTERSTATE FREIGHT LINES INC | | | SCAC4 |
| 28 | INTH | INTERSTATE LOGISTICS SERVICE INC | | | SCAC4 |
| 29 | INTHO | INTHO GmbH | | DE | VKM |
| 30 | INTI | INTERSTATE DISTRIBUTOR CO (INTERMOD | | | SCAC4 |
| 31 | INTJ | INTERNATIONAL TRANSFER SERVICE INC | | | SCAC4 |
| 32 | INTL | INNISFAIL TRANSFER LTD | | | SCAC4 |
| 33 | INTN | INDUSTRIAL TRANSPORTATION INC | | | SCAC4 |
| 34 | INTO | ITS TECHNOLOGIES & LOGISTICS LLC | | | SCAC4 |
| 35 | INTR | INTERIOR TRANSPORTATION INC | | | SCAC4 |
| 36 | INTR | INTERAIL | | AUS | TRAFFIC |
| 37 | INTRA | Innovatrain AG | | CH | VKM |
| 38 | INTS | INTERLAKE STEEL | | | PWRC |
| 39 | INTS | INTERSTATE TRANSIT INC | | | SCAC4 |
| 40 | INTSK | Slovenska kombinovana doprava INTRANS, a.s. | | SK | VKM |
| 41 | INTT | INTERSTATE TRANSPORT INC | | | SCAC4 |
| 42 | INTU | SEACUBE CONTAINERS LLC | | USA | BIC |
| 43 | INTU | INTERPOOL CONTAINER PTY., LTD. | | | PWRC |
| 44 | INTU | Interpool Container Pty | | | RSRV |
| 45 | INTU | INTERPOOL, INC. | | | SCAC4 |
| 46 | INTX | Interstate Commodities Inc. | 7/2005 (not listed); added 4/2007; eliminated 7/2007 | | NAKINA |
| 47 | INTX | *INTERNATIONAL TERMINALS | | | PWRC |
| 48 | INTX | +INTERSTATE COMMODITIES INC. | | | PWRC |
| 49 | INTX | INTERSTATE COMMODITIES INC | | | SCAC4 |
| 50 | INTZ | *INTEGRATED INGREDIENTS | | | PWRC |
| 51 | INTZ | *INTERPOOL LTD. | | | PWRC |
| 52 | INTZ | Interpool | | | RSRV |
| 53 | INTZ | INTERPOOL LTD. | | | SCAC4 |
