| 1 | ISA | Island Airlines, Inc. | IATA: IS, Callsign: Island, | USA | AVCODES |
| 2 | ISA | Island Air | Callsign: Island, | USA | AVCODES |
| 3 | ISAA | ISAACS MOVING & STORAGE | | | SCAC4 |
| 4 | ISAE | ISAAC, LEON | | | SCAC4 |
| 5 | ISAF | ISLAND SUPERIOR AIR FILTERS | | | SCAC4 |
| 6 | ISAF | ISAF S.A. | | RO | TRAFFIC |
| 7 | ISAF | ISAF SA | | RO | VKM |
| 8 | ISAH | IONICS MASS SPECTROMETRY GROUP INC | | | SCAC4 |
| 9 | ISAM | ISAM S.r.l. | | IT | VKM |
| 10 | ISAN | INLAND STATE AIR ENTERPRISES INC | | | SCAC4 |
| 11 | ISAP | INTERNATIONAL SEA & AIR SHIPPING | | | SCAC4 |
| 12 | ISAR | ISARIC TRANSPORT INC | | | SCAC4 |
| 13 | ISAR | Isarperle | | D | TRAFFIC |
| 14 | ISAU | NORDIC BULKERS AB | | | SCAC4 |
| 15 | ISAW | INLACO SAIGON | | | SCAC4 |
| 16 | ISAY | INTERNATIONAL SHIPPING AND LOGISTIC | | | SCAC4 |
