| 1 | IRS | Sirius | Callsign: Sirius, | UA | AVCODES |
| 2 | IRS | Sahand Airlines | Callsign: Sahand Air, | IR | AVCODES |
| 3 | IRSC | INDY RAIL CAR SERVICE | | | PWRC |
| 4 | IRSC | INTRANSIT CONTAINER INC | | | SCAC4 |
| 5 | IRSI | INGRAM REFRIGERATED SERVICES INC | | | SCAC4 |
| 6 | IRSI | International Rolling Stock Investment GmbH | | CH | TRAFFIC |
| 7 | IRSIG | International Rolling Stock Investment GmbH | | CH | TRAFFIC |
| 8 | IRSN | INTER RAIL SYSTEMS INC | | | SCAC4 |
| 9 | IRSU | IZELAAR SALES BV | | | SCAC4 |
| 10 | IRSX | TRANSPORTATION TECHNOLOGY CENTER IN | | | SCAC4 |
| 11 | IRSY | INDUSTRIAL TRANSPORTATION SYSTEMS I | | | SCAC4 |
| 12 | IRSZ | INTERPOOL RAIL SERVICES LTD. | | | PWRC |
| 13 | IRSZ | Interpool Rail Services | | | RSRV |
