| 6301 | LPTX | The Live Poultry Transit Co. (Palace Live Poultry Car Co.) | 7/1930-7/1935 | | NAKINA |
| 6302 | LPTX | The Live Poultry Transit Co. | 8/1920-7/1923 | | NAKINA |
| 6303 | LPTX | (North American Car Corp.) | Apr-38 | | NRHS |
| 6304 | LPTX | PALACE LIVE POULTRY CAR CO. [LIVE POULTRY TRANSIT CO.] (NATIONAL CAR CORP.) | | | PWRC |
| 6305 | LPTY | LOWNEY, PAUL TRANSPORT INC | | | SCAC3 |
| 6306 | LPU | Air Provence Charter | Callsign: Eurostar, Name changed to Virgin Express France (VEF) during 1998. | F | AVCODES |
| 6307 | LPUS | LINEA PENINSULAR INC | | | SCAC4 |
| 6308 | LPUT | LEISURE POOLS USA TRADING INC | | | SCAC4 |
| 6309 | LPV | Air Alps Aviation | IATA: A6 | | ICAO1 |
| 6310 | LPVE | LEP LASSEN CA | | | SCAC3 |
| 6311 | LPVG | LAKEPORT NAVIGATION COMPANY | | | SCAC3 |
| 6312 | LPVN | LEP INTERNATIONAL LTD | | | SCAC3 |
| 6313 | LPVP | LOZADA TRANSPORT SERVCES | | | SCAC4 |
| 6314 | LPVS | LAPORTES VAN & STORAGE LTD | | | SCAC3 |
| 6315 | LPVX | National Car Co. | 1/1945-7/1954; eliminated 10/1954 | | NAKINA |
| 6316 | LPVX | National Car Co. | Jan-52 | | NRHS |
| 6317 | LPVX | NATIONAL CAR CO. | | | PWRC |
| 6318 | LPWD | LATHROP WOODWORKS | | | SCAC4 |
| 6319 | LPWR | LOADPOWER | | | SCAC4 |
| 6320 | LPX | National Car Co. | 1/1950 | | NAKINA |
| 6321 | LPX | Fruit Growers Express Co. (reporting marks for Lewis Packing Co.) | 7/1937-1/1941 | | NAKINA |
| 6322 | LPX | Lewis Packing Co. | 7/1935 | | NAKINA |
| 6323 | LPX | Lewis Packing Co. (National Car Co.) | Apr-38 | | NRHS |
| 6324 | LPX | LEWIS PACKING CO. (NATIONAL CAR CO. [FRUIT GROWERS EXPRESS CO.]) | | | PWRC |
| 6325 | LPXI | LEAPSTAR TRANSPORTATION INC | | | SCAC4 |
| 6326 | LPXP | LOOP EXPRESS INC | | | SCAC3 |
| 6327 | LPXS | L P EXPRESS, LLC | | | SCAC4 |
| 6328 | LPXT | LYN PAX TRUCKING LTD | | | SCAC3 |
| 6329 | LPXU | PROMOCION EXPORTACION Y SERVICIOS | | E | BIC |
| 6330 | LPYA | LIEPAYA SHIPPING COMPANY LTD. | | | SCAC3 |
| 6331 | LPYH | LPY HOLDINGS | | | SCAC4 |
| 6332 | LPZA | LOPEZ, ADALBERTO | | | SCAC3 |
| 6333 | LPZA | LOPEZ RIVERA, ALFREDO | | | SCAC4 |
| 6334 | LPZB | LOPEZ BARRON, JUANA GUADALUPE | | | SCAC4 |
| 6335 | LPZD | LOPEZ & DUKES TRUCKING | | | SCAC4 |
| 6336 | LPZF | LOPEZ, FRANK G JR TRUCKING | | | SCAC3 |
| 6337 | LPZF | LOPEZ MONTIEL, ALBERTO | | | SCAC4 |
| 6338 | LPZI | LOPEZ IRIBE, JOSE LUIS | | | SCAC4 |
| 6339 | LPZJ | LOPEZ TRUCKING LLC | | | SCAC4 |
| 6340 | LPZL | LOPEZ, L B TRUCKING | | | SCAC3 |
| 6341 | LQ | Lebanese Air Transport | ICAO: LAQ, Callsign: LAT, Designator LQ recalled by IATA | RL | AVCODES |
| 6342 | LQ | Airpac Airlines, Inc. | ICAO: APC, Callsign: Airpac, Designator LQ* recalled by IATA | USA | AVCODES |
| 6343 | LQ | Air Astana | ICAO: AST, IATA Designator changed to 4L | KZ | AVCODES |
| 6344 | LQ | Air Guinea Cargo, S.A. | | GQ | AVCODES |
| 6345 | LQ | Skynet Asia Airways | ICAO: SNJ, Callsign: Newsky, Name changed to Solaseed Air. Designator 0E recalled by IATA | J | AVCODES |
| 6346 | LQ | Solaseed Air | ICAO: SNJ, Callsign: Newsky, Name changed from Skynet Asia Airways. IATA designator changed to 6J. Designator 0E recalled by IATA | J | AVCODES |
| 6347 | LQ | Lanmei Airlines (Cambodia) Co., Ltd. | ICAO: MKR, Callsign: Air Lanme, IATA Prefix: 961, AOC granted and due to commence operations on 09 October 2017. | K | AVCODES |
| 6348 | LQAA | LA FONFANA BALNCA, LTD. | | | SCAC3 |
| 6349 | LQAB | LA FONTANA CLARA. LTD, | | | SCAC3 |
| 6350 | LQAB | LINQ LOGISTICS | | | SCAC4 |
| 6351 | LQAC | LA FONTANA DORADA, LTD. | | | SCAC3 |
| 6352 | LQAC | LA FONTANA DORADA, LTD. | | | SCAC4 |
| 6353 | LQAD | LA FONTANA FLOTA, LTD. | | | SCAC3 |
| 6354 | LQAE | LA FONTANA NOBLA LTD. | | | SCAC3 |
| 6355 | LQAF | LA FONTANA NOVELA, LTD. | | | SCAC3 |
| 6356 | LQAF | LA FONTANA NOVELA, LTD. | | | SCAC4 |
| 6357 | LQAG | LA FONTANA PRIMA, LTD. | | | SCAC3 |
| 6358 | LQAG | LA FONTANA PRIMA, LTD. | | | SCAC4 |
| 6359 | LQAH | LA FONTANA PURA, LTD. | | | SCAC3 |
| 6360 | LQAI | LA FONTANA RICA, LTD. | | | SCAC3 |
| 6361 | LQAJ | LA FONTANA SIRENA, LTD. | | | SCAC3 |
| 6362 | LQBG | LEONHARDT & BLUMBERG | | | SCAC3 |
| 6363 | LQBI | LES QUAIS BERTRAND INC | | | SCAC4 |
| 6364 | LQCG | LIQUID CARGO INC | | | SCAC3 |
| 6365 | LQCR | LEVESQUE, CRAIG R | | | SCAC4 |
| 6366 | LQDL | LIQUIDUS LIMITED | | | SCAC3 |
| 6367 | LQFO | LISA QUALITY FOODS | | | SCAC3 |
| 6368 | LQGI | LATTI LOGISTICS INC | | | SCAC4 |
| 6369 | LQHS | LIGHTHOUSE SHIPPING CORPORATION | | | SCAC3 |
| 6370 | LQID | LIQUID TRANSPORTERS INC | | | SCAC3 |
| 6371 | LQIQ | LIQUISERVICE | | | SCAC3 |
| 6372 | LQKT | LIQUARI TRUCKING AND TRANSPORT | | | SCAC4 |
| 6373 | LQLI | LA QUALITY LOGISTICS INC | | | SCAC4 |
| 6374 | LQMS | LA QUINTA MARINE SERVICES, INC | | | SCAC3 |
| 6375 | LQNA | LERNA NAVIGATION COMPANY LIMITED | | | SCAC3 |
| 6376 | LQOC | LACKEY OIL CO | | | SCAC4 |
| 6377 | LQOI | LAVALLEE OIL INC | | | SCAC4 |
| 6378 | LQP | LAC QUI PARLE REGIONAL RAILROAD AUTHORITY | | | PWRC |
| 6379 | LQPC | LIQUID PARTNER CARRIERS | | | SCAC4 |
| 6380 | LQPD | LAPAD SHIPPING COMPANY LIMITED | | | SCAC3 |
| 6381 | LQRB | LOGISTIQUE RAYBEN | | | SCAC4 |
| 6382 | LQS | Lequios Airlines Co. Ltd. | Callsign: Lequios, | J | AVCODES |
| 6383 | LQTF | LIQUID TRANSFER INC | | | SCAC3 |
| 6384 | LQTS | LIQUID TRANSPORTATION SERVICE | | | SCAC3 |
| 6385 | LQUD | LIQUID TRANSPORT LLC | | | SCAC4 |
| 6386 | LR | Lineas Aereas Costarricenses S.A. (LACSA) | ICAO: LRC, Callsign: LACSA, IATA Prefix: 133, Name changed to Avianca Costa Rica | CR | AVCODES |
| 6387 | LR | Avianca Costa Rica S.A. | ICAO: LRC, Callsign: LACSA, IATA Prefix: 133, Name changed from Lineas Aereas Costarricenses S.A. (LACSA) | CR | AVCODES |
| 6388 | LR | Little River R.R. (Co.) | 7/1923-7/1954 | | NAKINA |
| 6389 | LR | Little River R.R. | 4/38-1/52 | | NRHS |
| 6390 | LR | *LITTLE RIVER RAILROAD CO. | | | PWRC |
| 6391 | LR | *LANDISVILLE RAILROAD | | | PWRC |
| 6392 | LRA | Little Red Air Service | Callsign: Little Red, | CDN | AVCODES |
| 6393 | LRA | Little Red Air Service | | | ICAO1 |
| 6394 | LRAA | LARAS TRUCKING INC | | | SCAC4 |
| 6395 | LRAB | LAHAI ROI TRUCKING | | | SCAC4 |
| 6396 | LRAC | LEE RACING INC | | | SCAC4 |
| 6397 | LRAD | LERAD | | | SCAC4 |
| 6398 | LRAF | Rīgas Autobusu Fabrika (RAF): Latvija | Real: RAF | LV | TRAFFIC |
| 6399 | LRAG | LDS RAGS | | | SCAC4 |
| 6400 | LRAI | LAIRD, R TRANSPORT INC | | | SCAC4 |
