| 301 | KAND | KANDILOUSA SHIPPING CORP | | | SCAC3 |
| 302 | KANE | KANE TRANSFER COMPANY | | | SCAC3 |
| 303 | KANG | KANGAROO EXPRESS, INC./KANGAROO PACKAGING SERVICE, INC | | | SCAC3 |
| 304 | KANG | KANGAROO PICK-UP AND DELIVERY SERVI | | | SCAC4 |
| 305 | KANH | KAN-HAUL INC | | | SCAC4 |
| 306 | KANI | KARNIL INTERNATIONAL TRANSPORT LTD | | | SCAC3 |
| 307 | KANK | KRAWCZYK, ANDREW | | | SCAC4 |
| 308 | KANL | KANE LIQUID FUELS INC | | | SCAC4 |
| 309 | KANM | KANN MANUFACTURING CORP | | | SCAC4 |
| 310 | KANN | KANE, E I INC. | | | SCAC3 |
| 311 | KANO | K-M TRUCK LINES INC | | | SCAC3 |
| 312 | KANO | K-M TRUCK LINES INC | | | SCAC4 |
| 313 | KANP | KANGAROO EXPRESS OF PUEBLO INC | | | SCAC3 |
| 314 | KANQ | KAUFFMAN & MINTEER INC | | | SCAC3 |
| 315 | KANS | KANSAS CARTAGE CO | | | SCAC3 |
| 316 | KANTO | Kanto Railway | Subsidiary of the Keisei Group | J | TRAFFIC |
| 317 | KANTOB | Kanto Bus Co. | | J | TRAFFIC |
| 318 | KANX | KANZA SERVICES, LLC | | | PWRC |
| 319 | KANX | KANZA SERVICES LLC | | | SCAC4 |
| 320 | KANY | KANEY TRANSPORTATION, INC | | | SCAC3 |
| 321 | KAO | JSC Aircompany KAPA | {IATA: G7, Callsign: Kazavia, IATA Prefix: 039, Name changed to JSC "KAPO Avia". Name changed from Kazan Aviation Production Association};SRCKEY=AVCODES | RUS | |
| 322 | KAO | Kazan Aviation Production Association | Callsign: Kazavia, Name changed to JSC Aircompany KAPA named after S.P. Gorbunov, Aircompany | RUS | AVCODES |
| 323 | KAO | JSC KAPO Avia | IATA: G7, Callsign: Kazavia, IATA Prefix: 039, Ceased operations. Name changed from JSC Aircompany KAPA. Name changed from Kazan Aviation Production Association | RUS | AVCODES |
| 324 | KAO | Kazan Aviation Production Association | | | ICAO1 |
| 325 | KAP | Cape Air | IATA: 9K, Callsign: Cair, Name changed to Hyannis Air Service, Inc. | USA | AVCODES |
| 326 | KAP | Hyannis Air Service, Inc. d/b/a Cape Air | IATA: 9K, Callsign: Cair, Name changed from Cape Air | USA | AVCODES |
| 327 | KAP | Cape Air | IATA: 9K | | ICAO1 |
| 328 | KAP | Kapos Volán | Part of the Keisei Electric Railway | H | TRAFFIC |
| 329 | KAPA | KAPLAN ENTERPRISES INC | | | SCAC3 |
| 330 | KAPA | KAPAY, CLARENCE | | | SCAC4 |
| 331 | KAPB | KAPPERM | | | SCAC4 |
| 332 | KAPC | K & P TRUCKING CO | | | SCAC3 |
| 333 | KAPC | K & P TRUCKING LLC | | | SCAC4 |
| 334 | KAPD | K & P DELIVERY | | | SCAC3 |
| 335 | KAPE | KAMPMANN ELEVATOR INC | | | SCAC3 |
| 336 | KAPI | KAP INC | | | SCAC3 |
| 337 | KAPK | Kaposvári Kisvasút | | H | TRAFFIC |
| 338 | KAPL | KAPLAN LUMBER CO | | | SCAC3 |
| 339 | KAPM | KAPMEY | | | SCAC4 |
| 340 | KAPO | KAPOWSIN MEATS INC | | | SCAC4 |
| 341 | KAPP | KAPITAL PRODUCE (2006) LTD | | | SCAC4 |
| 342 | KAPR | KAPP, RYAN | | | SCAC4 |
| 343 | KAPT | KAPS TRANSPORT LTD | | | SCAC3 |
| 344 | KAPU | KOMATSU AMERICA CORP | | USA | BIC |
| 345 | KAPU | Northland Seasonal Storage | | | RSRV |
| 346 | KAPU | NORTHLAND SEASONAL STORAGE | | | SCAC4 |
| 347 | KAPV | Kaposvári Városi Közlekedés | City: Kaposvár | H | TRAFFIC |
| 348 | KAPX | K.A. Powell (Canada) Ltd. | added 10/1953; 7/1954-10/1957; eliminated 7/1958 | | NAKINA |
| 349 | KAPX | K.A. Powell (Canada) Ltd. | added 10/53; 10/57; eliminated 7/58 | | NRHS |
| 350 | KAPX | K. A. POWELL (CANADA) LTD. | | | PWRC |
| 351 | KAQS | KASSOS MARITIME COMPANY | | | SCAC3 |
| 352 | KAR | Kar-Air O/Y | Callsign: Karair, Merged into Finnair | FIN | AVCODES |
| 353 | KAR | Kar-Air O/Y | IATA: KR, Callsign: Karair, Designator KR recalled by IATA. Merged into Finnair | FIN | AVCODES |
| 354 | KAR | Ikar, LLC | IATA: IK, Callsign: Krasjet, IATA Prefix: 770, Founded on 15 June 1993. Name changed to Ikar, LLC t/a Pegas Fly. | RUS | AVCODES |
| 355 | KAR | Ikar, LLC t/a Pegas Fly | IATA: IK, Callsign: Krasjet, IATA Prefix: 770, Founded on 15 June 1993. IATA designator changed to EO. Name changed from Ikar, LLC. | RUS | AVCODES |
| 356 | KAR | Ikar, LLC t/a Pegas Fly | IATA: EO, Callsign: Krasjet, IATA Prefix: 770, Founded on 15 June 1993. IATA designator changed from IK*. Name changed from Ikar, LLC. | RUS | AVCODES |
| 357 | KAR | Karosa | | CS | TRAFFIC |
| 358 | KARA | KAR TRANSPORT | | | SCAC4 |
| 359 | KARC | KARCHER, CHARLES A | | | SCAC3 |
| 360 | KARD | KARDUX TRANSFER INC | | | SCAC3 |
| 361 | KARE | KAR SERVICES | | | SCAC4 |
| 362 | KARH | KARRIERS INC | | | SCAC3 |
| 363 | KARL | KARLE CARRIAGE WORKS | | | SCAC3 |
| 364 | KARL | KAR ALLIANCE TRANSPORT LTD | | | SCAC4 |
| 365 | KARM | KARMO LTD | | | SCAC3 |
| 366 | KARMANN | Karmann Osnabrück | | D | TRAFFIC |
| 367 | KARO | KAPPICO, I TRUCK SERVICE INC | | | SCAC3 |
| 368 | KARO | Karo As Umweltschutz GmbH | | DE | VKM |
| 369 | KARP | KAPTUR ENTERPRISES INC | | | SCAC3 |
| 370 | KARP | KÁRPÁT Vasút Kft | | HU | VKM |
| 371 | KARQ | KARNES, LENDELL | | | SCAC3 |
| 372 | KARR | KARR OIL INC | | | SCAC4 |
| 373 | KARSAN | Karsan | | TR | TRAFFIC |
| 374 | KART | KART BROKERAGE SERVICES LLC | | | SCAC4 |
| 375 | KARU | WAKLER EXIM | | UZ | BIC |
| 376 | KARU | JV RKTFG ALAN LTD | | | SCAC4 |
| 377 | KARV | KAREVAN INC | | | SCAC3 |
| 378 | KARV | ČSAD Karviná a.s. | | CZ | TRAFFIC |
| 379 | KARW | KASARI TRUCKING INC | | | SCAC3 |
| 380 | KARX | General Electric Railcar Services Corp. | 1/1994; eliminated 10/1994 | | NAKINA |
| 381 | KARX | Hamilton Elevators | added 10/1980; eliminated 10/1989 | | NAKINA |
| 382 | KARX | Hamilton Elevators | added 10/80; eliminated 10/89 | | NRHS |
| 383 | KARX | General Electric Railcar Services Corp. | 1/94; eliminated 10/94 | | NRHS |
| 384 | KARX | (NATX) GENERAL ELECTRIC RAILCAR SERVICES CORP. [HAMILTON ELEVATORS] | | | PWRC |
| 385 | KARX | Hamilton Elevators | | | RSRV |
| 386 | KARY | KARYSTOS SHIPPING S A | | | SCAC4 |
| 387 | KAS | Kingston Air Services | Callsign: Kingston Air, | CDN | AVCODES |
| 388 | KAS | Air Company CAAS | Callsign: Pegas, | KS | AVCODES |
| 389 | KAS | Kingston Air Services | | | ICAO1 |
| 390 | KASA | KASPAR, J H OIL COMPANY | | | SCAC4 |
| 391 | KASB | KRAMBEC | | | SCAC4 |
| 392 | KASD | KAST, DAVE TRUCKING INC | | | SCAC3 |
| 393 | KASH | KASHS TRANSFER AND STORAGE | | | SCAC3 |
| 394 | KASH | KASTALIA SHIPPING COMPANY LIMITED | | | SCAC4 |
| 395 | KASH | Kashima railway company | | J | TRAFFIC |
| 396 | KASJ | K & S TRANSPORTATION COMPANY INC | | | SCAC3 |
| 397 | KASK | KAS TRUCKING INC | | | SCAC3 |
| 398 | KASK | KAS TRUCKING LLC | | | SCAC4 |
| 399 | KASL | KASSEL TRANSFER INC | | | SCAC3 |
| 400 | KASL | KASS FM LOGISTICS | | | SCAC4 |
