| 1 | IES | Gomel Engineer's Institute of the Ministry for Emergency Situations | | BY | AVCODES |
| 2 | IES | Inter-Island Air Services Ltd. | IATA: QW, Callsign: Inter Island, Desigantor QW recalled by IATA | WG | AVCODES |
| 3 | IESC | INTERNATIONAL EXHIBITION SERVICES I | | | SCAC4 |
| 4 | IESD | INGENIERIA EN SISTEMAS DE OPERACION | | | SCAC4 |
| 5 | IESG | INLAND EMPIRE STAGES LTD | | | SCAC4 |
| 6 | IESL | INTERNATIONAL EQUIPMENT SALES & LEA | | | SCAC4 |
| 7 | IESN | INTERRA ENERGY SERVICES INTERNATION | | | SCAC4 |
| 8 | IESO | INTERNATIONAL EQUIPMENT SALES CO | | | SCAC4 |
| 9 | IESP | INTERMODAL EXPRESS SERVICES INCORPO | | | SCAC4 |
| 10 | IESS | ITECH ENVIRONMENTAL SERVICES | | | SCAC4 |
| 11 | IESV | INTERNATIONAL ENVIRONMENTAL SERVICE | | | SCAC4 |
| 12 | IESW | IMPERIAL EAGLE SHIPPING LLC | | | SCAC4 |
| 13 | IESX | Alliant Energy | added 4/2000; 7/2000-7/2005 | | NAKINA |
| 14 | IESX | IES Utilities, Inc. | added 1/1996; eliminated 4/2000 | | NAKINA |
| 15 | IESX | Iowa Southern Utilities Co. | eliminated 1/1996 | | NAKINA |
| 16 | IESX | IESX Corp. | added 7/1981; eliminated 10/1987 | | NAKINA |
| 17 | IESX | Ivan E. Summa | added 4/1974; 1/1975-1/1980; eliminated 7/1981 | | NAKINA |
| 18 | IESX | Ivan E. Summa | added 4/74; 1/75-1/80; eliminated 7/81 | | NRHS |
| 19 | IESX | IESX Corp. | added 7/81; eliminated 10/87 | | NRHS |
| 20 | IESX | Iowa Southern Utilities Co. | eliminated 1/96 | | NRHS |
| 21 | IESX | IES Utilities, Inc. | added 1/96; eliminated 4/2000 | | NRHS |
| 22 | IESX | Alliant Energy | added 4/2000; 7/2000 | | NRHS |
| 23 | IESX | ALLIANT ENERGY [IES UTIITIES; IOWA SOUTHERN UTILITIES; IESX CORP.; IVAN E. SUMMA] | | | PWRC |
| 24 | IESX | IESX Corporation (Alliant Energy) | | | RSRV |
| 25 | IESX | ALLIANT ENERGY | | | SCAC4 |
