| Carrier Code | Carrier Name |
| IOLC | INTEROCEANICA LTDA (COMPANIA DE TRANSPORTE MARITIMO) |
| IONA | IONIA MANAGEMENT S A |
| IOSC | INTEROCEAN STEAMSHIP CORPORATION |
| IOSS | INTERNATIONAL OFF SHORE SERVICES INC |
| IOSU | INSTITUTE OF OCEANOGRAPHIC SCIENCES |
| IOTC | INTEROCEAN TANKER CORPORATION |
| IPCS | INTERNATIONAL PARCEL SERVICE LTD |
| IPCU | INDEPENDENT CONTAINER LINE LTD |
| IRNU | INTERPOOL CONTAINER PTY LTD |
| IRSC | INTRANSIT CONTAINER INC |
| IRT | INLAND RIVER TRANSPORTATION CORPORATION |
| IRTU | ISOTANK SERVICES LIMITED |
| ISBL | ISABELLA MARITIME LTD |
| ISCB | ISABELLA SHIPPING COMPANY LTD BERMUDA |
| ISCC | INTERNATIONAL SHIPPING COMPANY INC |
