| 1 | IW | Ryanair Ltd. | ICAO: RYR, Callsign: Ryanair, IATA designator changed to FR | IRL | AVCODES |
| 2 | IW | Air Liberte AOM | ICAO: AOM, Callsign: French Lines, IATA Prefix: 646, Name changed to Air Lib w.e.f. 22 September 2001. Name changed from AOM-Minerve S.A. d/b/a AOM French Airlines | F | AVCODES |
| 3 | IW | Minerve, S.A. | ICAO: MIN, Callsign: Minerve, IATA Prefix: 646, Name changed to AOM - Minerve, S.A. | F | AVCODES |
| 4 | IW | AOM-Minerve S.A. d/b/a AOM French Airlines | ICAO: AOM, Callsign: French Lines, IATA Prefix: 646, Name changed to Air Liberte AOM. Name changed to AOM-Minerve S.A. d/b/a AOM French Airlines March 1992. | F | AVCODES |
| 5 | IW | AOM-Minerve S.A. t/a Air Lib | ICAO: LIB, Callsign: Air Liberte, IATA Prefix: 646, Ceased operations on 17 Febraury 2003. Name changed to Air Lib w.e.f. 22 September 2001. IATA changed from VD. Name changed from AOM - Air Liberte | F | AVCODES |
| 6 | IW | International Air Bahama | Callsign: Airbahama, Founded in June 1968. Ceased operations on 18 May 1981. | BS | AVCODES |
| 7 | IW | Wings Abadi Airlines, PT. | ICAO: WON, Callsign: Wings Abadi, Commenced operations on 10 July 2003. Wholly owned subsidiary of Lion Air | RI | AVCODES |
| 8 | IW | Aerospace One S.A. | ICAO: OAN, Callsign: Hellas Cargo, IATA Prefix: 271, | GR | AVCODES |
| 9 | IWAC | IMPERIAL WESTERN PRODUCTS INC | | | SCAC4 |
| 10 | IWAG | Industriewaggon GmbH | | AT | VKM |
| 11 | IWAKB | Iwata Kenpoku Bus (Northern Iwate Transportation Inc.) | | J | TRAFFIC |
| 12 | IWAL | INTER FORWARDING CO INC | | | SCAC4 |
| 13 | IWAR | IWARE INC | | | SCAC4 |
| 14 | IWATE | Iwate Development Railway | | J | TRAFFIC |
| 15 | IWAU | I-WAY TRANSPORT INC. | | CDN | BIC |
| 16 | IWBS | INDUSTRIAL WATERBLAST SERVICES | | | SCAC4 |
| 17 | IWC | Inland Waterways Corp. | 1/1950-7/1954 | | NAKINA |
| 18 | IWC | Inland Waterways Corp. | Jan-52 | | NRHS |
| 19 | IWC | INLAND WATERWAYS CORP. | | | PWRC |
| 20 | IWCI | ILLINOIS WHOLESALE CASH REGISTER CO | | | SCAC4 |
| 21 | IWCT | IWC TRANSPORT CORP | | | SCAC4 |
| 22 | IWD | Iberworld Airlines S.A.U. | IATA: TY, Callsign: Iberworld, Name changed to Orbest Airlines | E | AVCODES |
| 23 | IWD | Orbest Orizonia Airlines S.A. | IATA: IP, IATA Prefix: 560, Founded in 1998 as Iberworld. - Commenced operations on 11 April 1998. - Ceased operations on 05 May 2013. Name changed from Iberworld Airlines S.A.U. w.e.f. 01 May 2011. ORBEST is a member of the ORIZONIA CORPORACION group | E | AVCODES |
| 24 | IWD | Iberworld | IATA: TY | | ICAO1 |
| 25 | IWDB | IMEX WAREHOUSE & DISTRIBUTION | | | SCAC4 |
| 26 | IWDP | INDUSTRIAL WASTE & SALVAGE | | | SCAC4 |
| 27 | IWDT | IWD TRANSPORT INC | | | SCAC4 |
| 28 | IWEL | I WHEEL LOGISTICS INC | | | SCAC4 |
| 29 | IWES | INTEGRATED WIND ENERGY SERVICES LLC | | | SCAC4 |
| 30 | IWGP | INTERNATIONAL WIRE GROUP INC | | | SCAC4 |
| 31 | IWGU | IWS INTERNATIONALE WEIN UND SPIRITUOSEN TRANSPORTE GMBH | | D | BIC |
| 32 | IWGX | INDUSTRIAL WASTE GROUP, LLC | | | PWRC |
| 33 | IWGX | INDUSTRIAL WASTE GROUP LLC | | | SCAC4 |
| 34 | IWHL | IWHEELS DEDICATED INC | | | SCAC4 |
| 35 | IWIC | INTEGRITY WINDOWS INC | | | SCAC4 |
| 36 | IWIG | Isle of Wight | | GB | TRAFFIC |
| 37 | IWIN | INTERSTATE WAREHOUSING INC | | | SCAC4 |
| 38 | IWKC | INTERNETFREIGHTNETWORK.COM | | | SCAC4 |
| 39 | IWL | Island Wings Limited | | BS | AVCODES |
| 40 | IWLQ | IMESON, WILLIAM A | | | SCAC4 |
| 41 | IWLU | IMPALA TERMINALS SWITZERLAND SARL | | CH | BIC |
| 42 | IWPI | INTERNATIONAL WOOD PROCESSORS INC | | | SCAC4 |
| 43 | IWPZ | IOWA POWER SERVICE | | | PWRC |
| 44 | IWRK | IRONWORKS | | | SCAC4 |
| 45 | IWRR | Intermountain Western R.R. | 1/1994 | | NAKINA |
| 46 | IWRR | Intermountain Western R.R. | Jan-94 | | NRHS |
| 47 | IWRR | *RETIRED 01-28-93 ATP (793) | | | PWRC |
| 48 | IWRR | *INTERMOUNTAIN WESTERN RAILROAD | | | PWRC |
| 49 | IWRU | IWS RUSSIA GMBH | | D | BIC |
| 50 | IWS | Aviainvest, Joint Stock Company | | RUS | AVCODES |
| 51 | IWS | Aviainvest | | | ICAO1 |
| 52 | IWSC | INTERNATIONAL WAREHOUSE SERVICES IN | | | SCAC4 |
| 53 | IWSI | INDUSTRIAL WAREHOUSE SERVICES INC | | | SCAC4 |
| 54 | IWSL | ID WALLEM SHIPMANAGEMENT LTD | | | SCAC4 |
| 55 | IWSN | INDUSTRIAL WASTE SERVICE INC | | | SCAC4 |
| 56 | IWSQ | IONIAN WAVE SHIPPING INC | | | SCAC4 |
| 57 | IWSU | WISCONSIN & SOUTHERN RAILROAD CO | | | SCAC3 |
| 58 | IWSU | WISCONSIN & SOUTHERN RAILROAD | | | SCAC4 |
| 59 | IWSX | Illinois-Wisconsin Sand & Gravel Co. | added 7/1972; 1/1975-1/1980; eliminated 10/1980 | | NAKINA |
| 60 | IWSX | Illinois-Wisconsin Sand & Gravel Co. | 1/75-1/80; eliminated 10/80 | | NRHS |
| 61 | IWSX | ILLINOIS-WISCONSIN SAND & GRAVEL CO | | | PWRC |
| 62 | IWSX | ILLINOIS-WISCONSIN SAND & GRAVEL CO | | | SCAC4 |
| 63 | IWSY | INTERWEST SYSTEMS INC | | | SCAC4 |
| 64 | IWTS | ISLAND WAY TRANS SERVICES INC | | | SCAC4 |
| 65 | IWTU | INTERNATIONAL WAREHOUSING AND TRANSPORT | | NL | BIC |
| 66 | IWTU | INTERNATIONAL WAREHOUSING AND TRANS | | | SCAC4 |
| 67 | IWUS | ISEWAN USA INC | | | SCAC4 |
| 68 | IWWR | INDIOS WESTERN WARE | | | SCAC4 |
| 69 | IWY | Interisland Airways Limited | IATA: JY, Callsign: Islandways, Name changed to Air Turks and Caicos (2003) Ltd | TC | AVCODES |
| 70 | IWY | Air Turks and Caicos (2003) Ltd | IATA: JY, Callsign: Islandways, Name changed to InterCaribbean Airways. Name changed from Interisland Airways Limited | TC | AVCODES |
| 71 | IWY | InterCaribbean Airways | IATA: JY, Callsign: Islandways, Name changed from Air Turks and Caicos (2003) Ltd. Name changed from Interisland Airways Limited | TC | AVCODES |
| 72 | IWY | Interisland Airways Limited | | | ICAO1 |
