| 1101 | IFRX | INFINITY RAIL LLC | | | SCAC4 |
| 1102 | IFRX | Infinity Rail | | USA | TRAFFIC |
| 1103 | IFS | Italy First | IATA: IF, Callsign: Riviera, Designator IF* recalled by IATA. ICAO callsign changed from Italy First | I | AVCODES |
| 1104 | IFS | International Flying Serivces | IATA: F4, Name changed to Eureca Srl | I | AVCODES |
| 1105 | IFS | Flying Services Srl | | I | AVCODES |
| 1106 | IFS | Italy First | | | ICAO1 |
| 1107 | IFS | International Freight Systems | | USA | TRAFFIC |
| 1108 | IFSA | INTERSTATE FREIGHT SYSTEMS INC | | | SCAC4 |
| 1109 | IFSB | ILLINI F S INC | | | SCAC4 |
| 1110 | IFSD | IFS DEDICATED INC | | | SCAC4 |
| 1111 | IFSE | INTERNATIONAL FREIGHT SERVICES | | | SCAC4 |
| 1112 | IFSG | INTERPORT FREIGHT SYSTEMS INC | | | SCAC4 |
| 1113 | IFSI | IFS INTERNATIONAL FREIGHT SYSTEMS I | | | SCAC4 |
| 1114 | IFSJ | INTERNATIONAL FIRST SERVICE USA INC | | | SCAC4 |
| 1115 | IFSK | INSTITUTE FOR SHIPBOARD EDUCATION | | | SCAC4 |
| 1116 | IFSM | IFS NEUTRAL MARITIME SERVICE INC | | | SCAC4 |
| 1117 | IFSN | INNOVATIVE FREIGHT SYSTEMS | | | SCAC4 |
| 1118 | IFSP | INTERNATIONAL FREIGHT SERVICES INC | | | SCAC4 |
| 1119 | IFSQ | INTERNATIONAL FLATBED SERVICES | | | SCAC4 |
| 1120 | IFSR | INTERNATIONAL FREIGHT SERVICES INC | | | SCAC4 |
| 1121 | IFSS | INLINE FIBERGLASS LTD | | | SCAC4 |
| 1122 | IFSU | INTERFACE4SOLUTIONS | | B | BIC |
| 1123 | IFSU | INTERLINK FREIGHT SYSTEMS | | | PWRC |
| 1124 | IFSU | Interlink Freight Systems | | | RSRV |
| 1125 | IFSV | INTERCON FLOAT SERVICE | | | SCAC4 |
| 1126 | IFT | Interflight (Air Charter) Ltd. | Callsign: Interflight, Turboprop operations | GB | AVCODES |
| 1127 | IFT | Interflight | | | ICAO1 |
| 1128 | IFT | Interfracht s.r.o. | | CZ | TRAFFIC |
| 1129 | IFTC | INTERNATIONAL FREIGHT TRANSPORT INC | | | SCAC4 |
| 1130 | IFTI | INFINITY TRANS INC | | | SCAC4 |
| 1131 | IFTP | ISLAND FARMS TRANSPORTATION | | | SCAC4 |
| 1132 | IFTR | INTEGRITY FUEL TRANSPORT | | | SCAC4 |
| 1133 | IFTU | LEIBNIZ INSTITUT FOR TROPOSPHERIC RESEARCH | | D | BIC |
| 1134 | IFTU | LEIBNIZ INSTITUT FOR TROPOSPHERIC R | | | SCAC4 |
| 1135 | IFVI | I N A FOOD SERVICE INC | | | SCAC4 |
| 1136 | IFWZ | INDEPENDENT FREIGHTWAY INC. | | | PWRC |
| 1137 | IFWZ | Independent Freightway | | | RSRV |
| 1138 | IFWZ | INDEPENDENT FREIGHTWAY INC. | | | SCAC4 |
| 1139 | IFX | International Flight Training Academy | Callsign: Ifta, | USA | AVCODES |
| 1140 | IFX | International Flight Training Academy | | | ICAO1 |
| 1141 | IG | Meridiana S.p.A. | ICAO: ISS, Callsign: Merair, IATA Prefix: 191, Merged with Eurofly S.p.A. | I | AVCODES |
| 1142 | IG | Alisarda S.p.A. | ICAO: ISS, Callsign: Alisarda, IATA Prefix: 191, change of name to Meridiana S.p.A. | I | AVCODES |
| 1143 | IG | Meridiana Fly S.p.A. | ICAO: EEZ, Callsign: Merair, IATA Prefix: 191, ICAO designator changed to ISS. Name changed to Meridiana Fly S.p.A. t/a Meridiana. Merged with Eurofly S.p.A. | I | AVCODES |
| 1144 | IG | Meridiana Fly S.p.A. t/a Meridiana | ICAO: ISS, Callsign: Meridiana, IATA Prefix: 191, Name changed to Air Italy S.p.A. w.e.f. from 01 Amrch 2018.ICAO designator changed to ISS. Name changed to Meridiana Fly S.p.A. t/a Meridiana. ICAO callsign changed from Merair. Merged with Eurofly S.p.A. | I | AVCODES |
| 1145 | IG | Air Italy S.p.A. | ICAO: ISS, Callsign: Air Italy, IATA Prefix: 191, Name changed from Meridiana Fly S.p.A. t/a Meridiana w.e.f. from 01 March 2018.ICAO designator changed to ISS. Name changed to Meridiana Fly S.p.A. t/a Meridiana. ICAO callsign changed from Merair. Merged with Eurofly S.p.A. | I | AVCODES |
| 1146 | IG HSB | IG Harzer Schmalspurbahnen e.V. | Wernigerode | D | privat-bahn.de |
| 1147 | IGA | SkyTaxi sp. z.o.o. | IATA: TE, Callsign: iguana, | PL | AVCODES |
| 1148 | IGA | Skytaxi | | | ICAO1 |
| 1149 | IGAB | Inlandsgods AB | 2001 - 2007 | S | svenska-lok.se |
| 1150 | IGAB | Inlandsgods AB | 2001 - 2007 | S | TRAFFIC |
| 1151 | IGAI | IGA INC | | | SCAC4 |
| 1152 | IGAM | IN THE GAME INC. | | | SCAC4 |
| 1153 | IGAS | INDUSTRIAL GAS DISTRIBUTORS | | | SCAC4 |
| 1154 | IGAS | INTERGAS d.o.o. BEOGRAD | | RS | VKM |
| 1155 | IGB | Industriebahngesellschaft Berlin mbH | Berlin | D | privat-bahn.de |
| 1156 | IGB | Industriebahngesellschaft mbH (IGB) | | D | TRAFFIC |
| 1157 | IGB | Industriebahn-Gesellschaft Berlin | | DE | VKM |
| 1158 | IGBA | IGB AUTOMOTIVE LTD | | | SCAC4 |
| 1159 | IGBL | INTERGLOBAL LOGISTICS INC | | | SCAC4 |
| 1160 | IGBR | ITS GLOBAL RELOCATION SERVICES | | | SCAC4 |
| 1161 | IGC | Iraq Gate | | IRQ | AVCODES |
| 1162 | IGCM | INTERNATIONAL GLASS & CERAMICS | | | SCAC4 |
| 1163 | IGCS | INDEPENDENT GLOBAL CARRIERS II LLC | | | SCAC4 |
| 1164 | IGCU | INDEV SHIPPING SERVICES | | | SCAC4 |
| 1165 | IGCX | INDUSTRIAL GENERATING CO. | | | PWRC |
| 1166 | IGCZ | INDIANA GRAIN CO. | | | PWRC |
| 1167 | IGE | Internationale Gesellschaft für Eisenbahnverkehr mbH | Hersbruck | D | privat-bahn.de |
| 1168 | IGE | Internationale Gesellschaft für Eisenbahnverkehr | | D | TRAFFIC |
| 1169 | IGE | IGE Bahntouristik | | DE | VKM |
| 1170 | IGEBA | Ingenieurgesellschaft Bahn mbH | Krumbach | D | privat-bahn.de |
| 1171 | IGEBA | IGeBa- Ingeniergesellschaft Bahn MbH | | DE | VKM |
| 1172 | IGEU | ALPSANNA LIMITED | | IRL | BIC |
| 1173 | IGEW | IGE \"Werrabahn Eisenach\" e.V | | DE | VKM |
| 1174 | IGGU | AS INGLE | | | SCAC4 |
| 1175 | IGHB | IG Hirzbergbahn e.V | | DE | VKM |
| 1176 | IGHL | IGH LOGISTICS INC | | | SCAC4 |
| 1177 | IGIC | IMPEX GLS INC | | | SCAC4 |
| 1178 | IGIE | ICE GROUP INC, THE | | | SCAC4 |
| 1179 | IGIH | IMPEX GROUP INC, THE | | | SCAC4 |
| 1180 | IGIN | INTEGRATED INDUSTRIES INC | | | SCAC4 |
| 1181 | IGIS | INCI GEMI ISLETME LTD STI | | | SCAC4 |
| 1182 | IGL | Air Transport Iglesias S.A. | Callsign: Atisa, | YV | AVCODES |
| 1183 | IGL | IGL sp. z o. o. | | PL | TRAFFIC |
| 1184 | IGLI | INTEGRES GLOBAL LOGISTICS INC | | | SCAC4 |
| 1185 | IGLO | INTELLIGENT LOGISTICS LLC | | | SCAC4 |
| 1186 | IGLOO | Agro-industrial works Igloopol | City: Dębica | PL | TRAFFIC |
| 1187 | IGLQ | INTERNATIONAL GROUND LOGISTICS LLC | | | SCAC4 |
| 1188 | IGMI | INTERNATIONAL GLOBAL METALS INC | | | SCAC4 |
| 1189 | IGMR | INGRAM READYMIX INC | | | SCAC4 |
| 1190 | IGMT | INGRAM BROTHERS LLC | | | SCAC4 |
| 1191 | IGN | Interguide Air Limited | Callsign: Divine Air, | WAN | AVCODES |
| 1192 | IGN | Interguide Air | | | ICAO1 |
| 1193 | IGN | International-Great Northern R.R. (Co). | 7/1930-7/1965 & 1/1975-1/1980 | | NAKINA |
| 1194 | IGN | International-Great Northern R.R. | 4/38-7/65 & 1/75-1/80 | | NRHS |
| 1195 | IGN | UP [MISSOURI PACIFIC] [INTERNATIONAL - GREAT NORTHERN RR] | | | PWRC |
| 1196 | IGN | International-Great Northern | | | RSRV |
| 1197 | IGN | International-Great Northern R.R. | | USA | TRAFFIC |
| 1198 | IGN | IG Nebenbahn Nordhessen e.V | | DE | VKM |
| 1199 | IGNI | IGNITION INC | | | SCAC4 |
| 1200 | IGNJ | IMAGE ENGINEERING | | | SCAC4 |
