| 4301 | KPM | Sky Prim Air | Callsign: Sky Primair, | MD | AVCODES |
| 4302 | KPML | K P M TRANSPORT LIMITED | | | SCAC3 |
| 4303 | KPMN | KITCHEN PRIDE MUSHROOM FARMS INC | | | SCAC4 |
| 4304 | KPMP | KAPAL MANAGEMENT PRIVATE LTD. | | | SCAC3 |
| 4305 | KPMQ | KAPITAN MEDVETSKIY SHIPPING CO LTD, | | | SCAC3 |
| 4306 | KPMT | KUHL, PAM HORSE TRANSPORTATION | | | SCAC3 |
| 4307 | KPMV | KOKOMO PROFESSIONAL MOVERS | | | SCAC3 |
| 4308 | KPND | KITTS PICKUP & DELIVERY | | | SCAC3 |
| 4309 | KPND | KITTS TRANSFER & STORAGE INC | | | SCAC4 |
| 4310 | KPNL | KURTZ, P & L INC | | | SCAC3 |
| 4311 | KPNS | KEELEN, PAT & SONS INC | | | SCAC3 |
| 4312 | KPNT | KILLING PRODUCTIONS, THE | | | SCAC4 |
| 4313 | KPNU | «SMART LOGISTICS INTERNATIONAL» CO. LTD. | | RUS | BIC |
| 4314 | KPO | Nxt Jet, Inc. | Callsign: Krypto, | USA | AVCODES |
| 4315 | KPOC | KNOTTY PINE OIL CO INC | | | SCAC4 |
| 4316 | KPOL | KONPOLIS SHIPPING CORPORATION | | | SCAC3 |
| 4317 | KPOV | KUPRIANOV CO | | | SCAC3 |
| 4318 | KPPL | KNAPPLE INC | | | SCAC3 |
| 4319 | KPPO | KNAPP OIL CO INC | | | SCAC4 |
| 4320 | KPPS | KIPPS TRANSPORT COMPANY | | | SCAC3 |
| 4321 | KPPU | Krakowskie Przedsiębiorstwo Przewozowo-Usługowe, sp. z o.o. | City: Krakow | PL | TRAFFIC |
| 4322 | KPPX | Kraton Polymers U.S. LLC | added 10/2001; 7/2005 | | NAKINA |
| 4323 | KPPX | KRATON POLYMERS US, LLC. | | | PWRC |
| 4324 | KPPX | KRATON Polymers US | | | RSRV |
| 4325 | KPPX | KRATON POLYMERS U S LLC | | | SCAC4 |
| 4326 | KPQH | KAPITAN POMERANTS SHIPPING COMPANY | | | SCAC3 |
| 4327 | KPR | Kapa Air Ltd. | Callsign: Air Kapa, | GR | AVCODES |
| 4328 | KPR | Kelowna Pacific Ry. Ltd. | 7/2005 | | NAKINA |
| 4329 | KPR | KELOWNA PACIFIC RAILWAY, LTD. | | | PWRC |
| 4330 | KPR | Kelowna Pacific Railway | | | RSRV |
| 4331 | KPR | KELOWNA PACIFIC RAILWAY LTD | | | SCAC4 |
| 4332 | KPR | Kelowna Pacific Railway, Ltd. | | USA | TRAFFIC |
| 4333 | KPRC | K-PAX RACING LLC | | | SCAC4 |
| 4334 | KPRI | K P R INC | | | SCAC4 |
| 4335 | KPRL | K PAX RACING LLC | | | SCAC4 |
| 4336 | KPRM | KENILWORTH/PARKSIDE RESIDENT MANAGE | | | SCAC3 |
| 4337 | KPRR | KODAK PARK RAILROAD | | | PWRC |
| 4338 | KPRR | Kodak Park Railroad | | | RSRV |
| 4339 | KPRX | Western Light & Telephone Co., Inc. | 1/1952-7/1954; 10/1957-4/1961 (not listed) | | NAKINA |
| 4340 | KPRX | Kansas Power Co., Division of Western Light & Telephone Co., Inc. | 4/1947-1/1950 | | NAKINA |
| 4341 | KPRX | Kansas Power Co. | 1/1945-1/1946 | | NAKINA |
| 4342 | KPRX | Crystal Petroleum & Refining Co. | 7/1923 | | NAKINA |
| 4343 | KPRX | Western Light & Telephone Co., Inc. | 1/52-4/61 | | NRHS |
| 4344 | KPRX | *CRYSTAL PETROLEUM & REFINING CO. | | | PWRC |
| 4345 | KPRX | *WESTERN LIGHT & TELEPHONE CO., INC. [KANSAS POWER CO.] | | | PWRC |
| 4346 | KPS | Crystal Thai Airlines Co., Ltd | Callsign: Crystal Thai, | T | AVCODES |
| 4347 | KPSC | KENDRICK PAPER STOCK COMPANY INC | | | SCAC4 |
| 4348 | KPSH | KIPLING SHIPPING INC | | | SCAC3 |
| 4349 | KPSH | KHEOPS INTERNATIONAL INC | | | SCAC4 |
| 4350 | KPSP | KEEPSAK | | | SCAC4 |
| 4351 | KPSQ | KISSEL, PATRICK SR | | | SCAC3 |
| 4352 | KPST | KPS TRUCKING CO INC | | | SCAC3 |
| 4353 | KPST | KINGS PASTRY | | | SCAC4 |
| 4354 | KPSU | KANTO-PPC (SHANGHAI) INC. | | PRC | BIC |
| 4355 | KPT | Kapital Aviation | Callsign: Balado, | GB | AVCODES |
| 4356 | KPT | KPT Rail s.r.o. | | CZ | TRAFFIC |
| 4357 | KPTE | | City: Ewpatoria | UA | TRAFFIC |
| 4358 | KPTG | KNIGHT, PETE TRUCKING COMPANY | | | SCAC3 |
| 4359 | KPTG | K & P TRUCKING INC | | | SCAC4 |
| 4360 | KPTH | KHERA, PS TRANSPORTATION LTD | | | SCAC4 |
| 4361 | KPTI | K & P TRUCKING INCORPORATED | | | SCAC3 |
| 4362 | KPTL | K & P TRUCKING | | | SCAC4 |
| 4363 | KPTM | KNAPP, T MERLE INC | | | SCAC3 |
| 4364 | KPTN | KIRKPATRICK TRUCKING INC | | | SCAC3 |
| 4365 | KPTO | K & P TRANS INC | | | SCAC4 |
| 4366 | KPTR | KAPTRAN INC | | | SCAC3 |
| 4367 | KPTR | K & P TRUCKING SERVICES INC | | | SCAC4 |
| 4368 | KPTS | KAPITAN SILIN SHIPPING CO LTD, THE | | | SCAC3 |
| 4369 | KPTS | K P TRANSPORT INC | | | SCAC4 |
| 4370 | KPTT | KEMPER TRANSPORTATION LLC | | | SCAC4 |
| 4371 | KPTU | KONTEINERNIE PEREVOZKI LLP | | | SCAC4 |
| 4372 | KPTY | KAMP TRUCKING LLC | | | SCAC4 |
| 4373 | KPUC | Kitchener Public Utilities Commission | | CDN | TRAFFIC |
| 4374 | KPUD | KINDLES PICK-UP AND DELIVERY SERVIC | | | SCAC3 |
| 4375 | KPVS | KRAMER PILOT VEHICLE SERVICES LTD | | | SCAC4 |
| 4376 | KPX | Kaw Paving Co. | 1/1943-4/1961 (not listed) | | NAKINA |
| 4377 | KPX | Kaw Paving Co. | 1/52-4/61 | | NRHS |
| 4378 | KPX | KAW PAVING CO. | | | PWRC |
| 4379 | KPXI | KAPEX | | | SCAC3 |
| 4380 | KPXN | KP TRANSPORTATION | | | SCAC4 |
| 4381 | KPXX | The Andersons-Rail Group | added 10/2004; 7/2005 | | NAKINA |
| 4382 | KPXX | Progress Rail Services Corp. | added 7/1996; 7/2000; eliminated 10/2004 | | NAKINA |
| 4383 | KPXX | Electric Fuels Corp. | added 7/1994; eliminated 7/1996 | | NAKINA |
| 4384 | KPXX | Electric Fuels Corp. | added 7/94; eliminated 7/96 | | NRHS |
| 4385 | KPXX | Progress Rail Services Corp. | added 7/96; 7/2000 | | NRHS |
| 4386 | KPXX | THE ANDERSONS-RAIL GROUP [PROGRESS RAIL SERVICES CORP.; ONE EQUITY PARTNERS LLC](ELECTRIC FUELS CORP.) | | | PWRC |
| 4387 | KPXX | Progress Rail Services Corporation (The Andersons) | | | RSRV |
| 4388 | KPXX | ANDERSONS INC, THE | | | SCAC4 |
| 4389 | KPZT | KUPIETZ TRUCKING | | | SCAC3 |
| 4390 | KQ | Kenya Airways | ICAO: KQA, Callsign: Kenya, IATA Prefix: 706, | EAK | AVCODES |
| 4391 | KQA | Kenya Airways | IATA: KQ, Callsign: Kenya, IATA Prefix: 706, | EAK | AVCODES |
| 4392 | KQA | Kenya Airways | IATA: KQ | | ICAO1 |
| 4393 | KQA | Kenya Airways Ltd. | | EAK | TRAFFIC |
| 4394 | KQAT | K A T | | | SCAC4 |
| 4395 | KQC | KINGS & QUEENS COACHES INC | | | SCAC4 |
| 4396 | KQMT | K-MOTION | | | SCAC4 |
| 4397 | KQNL | KING NAVIGATION LTD | | | SCAC3 |
| 4398 | KQOC | KELLE OIL COMPANY | | | SCAC4 |
| 4399 | KQOL | K-Q-OIL | | | SCAC4 |
| 4400 | KQRT | KRT INC | | | SCAC4 |
