| 1 | IMR | Imaer | Callsign: Imaer, | P | AVCODES |
| 2 | IMR | Imaer | | | ICAO1 |
| 3 | IMRD | IRON MOUNTAIN RECORDS | | | SCAC4 |
| 4 | IMRF | INTERNATIONAL MOTOR FREIGHT INC | | | SCAC4 |
| 5 | IMRG | IMR METALLURGICAL RESOURCES AG | | | SCAC4 |
| 6 | IMRI | INTERNATIONAL MARINE SALVAGE INC | | | SCAC4 |
| 7 | IMRK | INTERMARK TRANSPORT INC | | | SCAC4 |
| 8 | IMRL | Iowa Chicago and Eastern R.R. Corp. | added 10/2002; added 1/2003; 7/2005; eliminated 1/2010 | | NAKINA |
| 9 | IMRL | I & M Rail Link, LLC | added 7/1997; 7/2000; eliminated 10/2002; eliminated 1/2003 | | NAKINA |
| 10 | IMRL | I & M Rail Link, LLC | added 7/97; 7/2000 | | NRHS |
| 11 | IMRL | IOWA, CHICAGO & EASTERN RAILROAD [I & M RAIL LINK LLC; ILLINOIS & MISSOURI RAIL LINK] | | | PWRC |
| 12 | IMRL | Illinois and Missouri Rail Link (Iowa, Chicago and Eastern Railroad) | | | RSRV |
| 13 | IMRL | I & M Rail Link, LLC | | USA | TRAFFIC |
| 14 | IMRN | INTERNATIONAL MARINE TRANSPORT, INC. | | | SCAC1 |
| 15 | IMRN | IMMEDIATE AIR CARGO TRANSIT INC | | | SCAC4 |
| 16 | IMRO | ITALIAN MOTORS LTD | | | SCAC4 |
| 17 | IMRR | Illinois & Midland R.R. Inc. | added 7/1996; 7/2000-7/2005 | | NAKINA |
| 18 | IMRR | Illinois & Midland R.R. Inc. | added 7/96; 7/2000 | | NRHS |
| 19 | IMRR | ILLINOIS & MIDLAND RAILROAD | | | PWRC |
| 20 | IMRR | Illinois and Midland Railroad | | | RSRV |
| 21 | IMRR | ILLINOIS & MIDLAND RAILROAD INC | | | SCAC4 |
| 22 | IMRR | Illinois and Midland | | USA | TRAFFIC |
| 23 | IMRS | IMPERIAL XPRESSS MIDLAND ONT | | | SCAC4 |
| 24 | IMRX | Imperial Refineries Corp. | added 7/1955; 10/1957; eliminated 4/1959 | | NAKINA |
| 25 | IMRX | Central States Oil Co. | 1/1941-7/1954; eliminated 7/1955 | | NAKINA |
| 26 | IMRX | Imperial Refineries Co. | 7/1937-4/1938 | | NAKINA |
| 27 | IMRX | Imperial Refining Co. (Imperial Refineries) | 7/1932-7/1935 | | NAKINA |
| 28 | IMRX | Imperial Refining Co. | 8/1920-7/1930 | | NAKINA |
| 29 | IMRX | Imperial Refineries | Apr-38 | | NRHS |
| 30 | IMRX | Central States Oil Co. | 1/52; eliminated 7/55 | | NRHS |
| 31 | IMRX | Imperial Refineries Corp. | added 7/55; 10/57 | | NRHS |
| 32 | IMRX | IMPERIAL REFINERIES CORP. (CENTRAL STATES OIL CO.) | | | PWRC |
| 33 | IMRZ | IOWA INTERSTATE RAILROAD | | | PWRC |
| 34 | IMRZ | IOWA INTERSTATE RAILROAD LTD | | | SCAC4 |
