| 201 | IAY | Daedalos Flugbetriebs GmbH | Callsign: Iason, | A | AVCODES |
| 202 | IAY | Deadalos Flugtbetriebs | | | ICAO1 |
| 203 | IAZ | Italia Tour Airlines S.p.A. | IATA: OI, AOC license was suspended by ENAC on 30 November 2009. | I | AVCODES |
| 204 | IB | Inntalbahn KG | | DE | VKM |
| 205 | IBA | Lineas Aereas Iberoamericanas | Callsign: Aerolai, | RCH | AVCODES |
| 206 | IBAB | Inlandsbanan AB | 1993 - | S | svenska-lok.se |
| 207 | IBAB | Inlandsbanan AB | 1993 - | S | TRAFFIC |
| 208 | IBAB | Inlandsbanan AB | | SE | VKM |
| 209 | IBAI | IBAIZABAL MANAGEMENT SERVICES S L | | | SCAC4 |
| 210 | IBAR | IBARRA RAMOS, JOSE JAIME | | | SCAC4 |
| 211 | IBAT | IBARRAS TRUCKING | | | SCAC4 |
| 212 | IBB | Binter Canarias, S.A. | IATA: NT, | E | AVCODES |
| 213 | IBB | Binter Canarias | IATA: NT | | ICAO1 |
| 214 | IBB | Binter Canarias | | E | TRAFFIC |
| 215 | IBBT | INNER BAY BOATS | | | SCAC4 |
| 216 | IBBU | U B C LTD | | | SCAC4 |
| 217 | IBC | Ibicenca Air, S.L. | Callsign: Ibicence, | E | AVCODES |
| 218 | IBC | Ibex Air Charter S.A.R.L. | Callsign: Ibex Charter, | RL | AVCODES |
| 219 | IBC | Ibicenca Air | | | ICAO1 |
| 220 | IBC | Imperial Bus Company | City: Rainham (Essex) | GB | TRAFFIC |
| 221 | IBCK | IBC TRUCKING LLC | | | SCAC4 |
| 222 | IBCO | I B C | | | SCAC4 |
| 223 | IBCQ | INTERNATIONAL BONDED COURIERS INC | | | SCAC4 |
| 224 | IBCT | IBRAHIM TRUCKING | | | SCAC4 |
| 225 | IBCU | DEN HARTOGH DRY BULK LOGISTICS LTD | | GB | BIC |
| 226 | IBCU | U B C LTD | | | SCAC4 |
| 227 | IBCX | Indiana Boxcar Corp. | 7/2000-7/2005 (not listed) | | NAKINA |
| 228 | IBCX | Iowa State Brand Creameries (North Western Refrigerator Line Co.) | 7/1935 | | NAKINA |
| 229 | IBCX | TTX Co. | added 10/2003 | | NAKINA |
| 230 | IBCX | Indiana Boxcar Corp. | Jul-00 | | NRHS |
| 231 | IBCX | INDIANA BOXCAR CORPORATION | | | PWRC |
| 232 | IBCX | Indiana Boxcar Corporation | | | RSRV |
| 233 | IBCX | INDIANA BOXCAR CORPORATION | | | SCAC4 |
| 234 | IBDC | IBARRA, FRANCISCO TRUCKING | | | SCAC4 |
| 235 | IBE | Iberia Airlines | IATA: IB | | ICAO1 |
| 236 | IBER | Iberia | | E | TRAFFIC |
| 237 | IBERC | IBERCARGORAIL, S.A. | | ES | VKM |
| 238 | IBERT | IBERTIF FERROCARRILES, S.A. | | ES | VKM |
| 239 | IBF | Ing Büro Förster | | DE | VKM |
| 240 | IBFU | DEN HARTOGH DRY BULK LOGISTICS LTD | | GB | BIC |
| 241 | IBG | Ice Bridge | Callsign: Springfield Air, | USA | AVCODES |
| 242 | IBG | Springfield Air | Callsign: Ice Bridge, | USA | AVCODES |
| 243 | IBIA | IBI ARMORED SERVICES INC | | | SCAC4 |
| 244 | IBIC | INFLATABLE BOATWORKS INC | | | SCAC4 |
| 245 | IBIS | IBIS SHIPPING LLC | | | SCAC4 |
| 246 | IBIT | IBI SECURED TRANSPORT INC | | | SCAC4 |
| 247 | IBJ | Air Taxi & Charter International, S.L. | Callsign: Ibertaxi, | E | AVCODES |
| 248 | IBK | Norwegian Air International Ltd. | IATA: D8, Callsign: Nortrans, IATA Prefix: 329, IATA designator changed to D8 | IRL | AVCODES |
| 249 | IBK | Norwegian Air International Ltd. | IATA: D8, Callsign: Nortrans, IATA Prefix: 329, IATA designator changed from D8* | IRL | AVCODES |
| 250 | IBK | Norwegian Air International Ltd. | IATA: D8, Callsign: Nortrans, IATA designator changed from D8* | IRL | AVCODES |
| 251 | IBKM | INDUSTRIAL BUCKETS DE MEXICO SA DE | | | SCAC4 |
| 252 | IBKU | INTERBULK,INC | | USA | BIC |
| 253 | IBKU | Interbulk,Inc | | | RSRV |
| 254 | IBL | IBL Aviation Ltd | Callsign: Catovair, | MUS | AVCODES |
| 255 | IBL | IBL Aviation | | | ICAO1 |
| 256 | IBL | Ingenierbüro Lohr | | DE | VKM |
| 257 | IBLC | I & B LOGISTICS INC | | | SCAC4 |
| 258 | IBLD | IRONLAKE BUSINESS LTD | | | SCAC4 |
| 259 | IBLT | IBL TRANSPORT CO LTD | | | SCAC4 |
| 260 | IBLU | INBULK TECHNOLOGIES LTD | | GB | BIC |
| 261 | IBLU | INBULK TECHNOLOGIES LTD | | | SCAC4 |
| 262 | IBME | INTERLINES - BLANKENSHIP MTR | | | PWRC |
| 263 | IBMS | IBARRAS IMPORTS | | | SCAC4 |
| 264 | IBMU | JSC INFOTECH-BALTIKA-M | | RUS | BIC |
| 265 | IBMZ | INTERNATIONAL BUSINESS CORP. | | | PWRC |
| 266 | IBN | INDUSTRIAL BUS LINES INC | | | SCAC4 |
| 267 | IBNU | INTERPOOL CONTAINER PTY LIMITED | | | PWRC |
| 268 | IBNU | Interpool Container Pty | | | RSRV |
| 269 | IBOX | TTX Co. | added 10/2003; 7/2005 | | NAKINA |
| 270 | IBOX | TTX CO. | | | PWRC |
| 271 | IBOX | TTX COMPANY | | | SCAC4 |
| 272 | IBPX | Trinity Industries Leasing Co. | added 7/1995; 7/2000-7/2005 | | NAKINA |
| 273 | IBPX | IBP, Inc. | added 5/1983; 1/1994; eliminated 7/1995 | | NAKINA |
| 274 | IBPX | Merchants Despatch Transportation Corp. | added 1/1961; 4/1961-4/1970; eliminated 1/1973 | | NAKINA |
| 275 | IBPX | Merchants Despatch Transportation Corp. | 4/61-4/70; eliminated 1/73 | | NRHS |
| 276 | IBPX | IBP, Inc. | added 5/83; 1/94; eliminated 7/95 | | NRHS |
| 277 | IBPX | Trinity Industries Leasing Co. | added 7/95; 7/2000 | | NRHS |
| 278 | IBPX | *MERCHANTS DESPATCH TRANSPORTATION CORP. | | | PWRC |
| 279 | IBPX | +TRINITY INDUSTRIES LEASING COMPANY (TYSON FOODS, INC., LESSEE)[IBP, INC; IOWA BEEF PACKERS] | | | PWRC |
| 280 | IBPX | Iowa Beef Packers (Trinity Industries Leasing Co.) | | | RSRV |
| 281 | IBPX | IBP, INC. | | | SCAC4 |
| 282 | IBR | Ibertour Servicios Aereos S.L.U. | Callsign: Ibertour, | E | AVCODES |
| 283 | IBR | Ibertour Servicios Aereos | | | ICAO1 |
| 284 | IBR | IRON BULL RAILROAD CO. | | | PWRC |
| 285 | IBR | IRON BULL RAILORAD COMPANY | | | SCAC4 |
| 286 | IBRR | IBARRA ESPINOZA, VICTOR H | | | SCAC4 |
| 287 | IBRU | IBERO LINES | | | SCAC4 |
| 288 | IBS | IBIS | Callsign: Spider, | B | AVCODES |
| 289 | IBS | Flying Partner | | B | AVCODES |
| 290 | IBS | Compania Operadora de Corto y Medio Radio Iberia Express, S.A.U | IATA: I2, Callsign: Iberexpres, IATA Prefix: 060, | E | AVCODES |
| 291 | IBSH | I BEAM SHIPPING COMPANY LIMITED | | | SCAC4 |
| 292 | IBSP | I BLADE SHIPPING COMPANY LIMITED | | | SCAC4 |
| 293 | IBSR | INGRAM BROTHERS SERVICES LLC | | | SCAC4 |
| 294 | IBSW | ICE BIRD SHIPPING SA | | | SCAC4 |
| 295 | IBSY | INLAND BARGE SERVICE INC | | | SCAC4 |
| 296 | IBT | Ibertrans Aerea, S.L. | Callsign: Ibertrans, | E | AVCODES |
| 297 | IBT | Ibertrans Aerea | | | ICAO1 |
| 298 | IBT | International Bridge & Terminal Co. | 1/1975-1/1994; added 7/1998; 7/2000-7/2005 | | NAKINA |
| 299 | IBT | International Bridge & Terminal Co. | 1/75-1/94; added 7/98; 7/2000 | | NRHS |
| 300 | IBT | INTERNATIONAL BRIDGE & TERMINAL | | | PWRC |
