| 1 | NA | North American Airlines, Inc. | ICAO: NAO, Callsign: North American, IATA Prefix: 455, Founded in 1989. Ceased operations on 07 June 2014. Designator NA reinstated by IATA. IATA designator changed from XG | USA | AVCODES |
| 2 | NA | Executive Air Charter | ICAO: EXK, IATA designator changed to OW | PRI | AVCODES |
| 3 | NA | National Airlines | ICAO: NAL, Callsign: National, Merged in Pan Am during 1980. | USA | AVCODES |
| 4 | NA | Espana, Direccion General De Aviacion Civil Y Telecomunicaciones | ICAO: ENA, Callsign: ENA, Designator NA recalled by IATA | E | AVCODES |
| 5 | NA | Nesma Airlines Company Ltd. | ICAO: NMA, Callsign: Nesma, Commenced operations on on 18 July 2010. | ET | AVCODES |
| 6 | NAA | National Oceanic And Atmospheric Administration | Callsign: Noaa, ICAO designator changed to NOA | USA | AVCODES |
| 7 | NAA | Airmore Aviation | IATA: MO, Callsign: National, | GB | AVCODES |
| 8 | NAA | Norwegian Air Argentina S.A.U. | IATA: DN, Callsign: Noruega, Commenced operations on 16 October 2018. | RA | AVCODES |
| 9 | NAA | National Oceanic and Atmospheric Administration | | | ICAO1 |
| 10 | NAAB | NAAB, STEVE | | | SCAC3 |
| 11 | NAAB | NATIVE DAWN FISHING LTD | | | SCAC4 |
| 12 | NAAD | NEBRASKA ATLANTIC TRANSPORTATION IN | | | SCAC4 |
| 13 | NAAE | NOBODY AUTO TRANSPORT INC | | | SCAC4 |
| 14 | NAAF | NORTH AMERICAN TRANSPORT SERVICES L | | | SCAC4 |
| 15 | NAAF | Namibian Air Force | | NAM | TRAFFIC |
| 16 | NAAG | NORTH AMERICAN AGENCIES OF TEXAS | | | SCAC3 |
| 17 | NAAG | NORTH AMERICAN CARRIERS INC | | | SCAC4 |
| 18 | NAAR | NAVIERAS ARMAS | | | SCAC3 |
| 19 | NAAS | NORTH AMERICAN AUTO LOGISTICS LLC | | | SCAC4 |
| 20 | NAAT | NATIONAL TRANSIT LEASING CORP | | | SCAC3 |
| 21 | NAB | Mina Airline Company | | ET | AVCODES |
| 22 | NAB | Niger Air Cargo | IATA: NO, Callsign: Niger Cargo, IATA Prefix: 591, | RN | AVCODES |
| 23 | NAB | Mina Airline Company | | | ICAO1 |
| 24 | NABC | NATIONAL BULK CARRIERS INC | | | SCAC3 |
| 25 | NABD | NEBI AND SONS TRUCKING | | | SCAC4 |
| 26 | NABF | NORTH ATLANTIC BALTIC FREIGHT CONFE | | | SCAC3 |
| 27 | NABG | NATIONAL BAGGAGE SERVICE | | | SCAC3 |
| 28 | NABG | NAVARROS TRUCKING | | | SCAC4 |
| 29 | NABH | NEW ABILITY SHIPPING INC | | | SCAC4 |
| 30 | NABI | NAB TRUCKING CO | | | SCAC3 |
| 31 | NABK | NATIONAL BOOK CONSOLIDATORS INC | | | SCAC3 |
| 32 | NABL | N A B TRUCKING LINE CORP | | | SCAC3 |
| 33 | NABR | NORTH AMERICAN BULK TRANSPORT INC | | | SCAC4 |
| 34 | NABU | ECST CONTAINER SERVICES & TRADING GMBH | | D | BIC |
| 35 | NABU | ECST CONTAINER SERVICES & TRADING GMBH. | | | PWRC |
| 36 | NABU | Ecst Container Services and Trading | | | RSRV |
| 37 | NABU | ECST EXPRESS CONTAINER SERVICES & | | | SCAC3 |
| 38 | NABU | ECST CONTAINER SERVICES & TRADING G | | | SCAC4 |
| 39 | NABV | NEW AGE BEVERAGE COMPANY | | | SCAC4 |
| 40 | NABW | NABERS SOLUTIONS LLC | | | SCAC4 |
| 41 | NABX | NARRAGANSETT BAY | | | PWRC |
| 42 | NABZ | NABISCO COMPANY | | | PWRC |
| 43 | NAC | Northern Air Cargo, Inc. | IATA: NC, Callsign: Yukon, IATA Prefix: 345, ICAO callsign changed from Northern Air Cargo. Name changed to Northern Air Cargo, LLC. | USA | AVCODES |
| 44 | NAC | Northern Air Cargo, Inc. | IATA: NC, Callsign: Northern Air Cargo, IATA Prefix: 345, ICAO callsign changed to Yukon | USA | AVCODES |
| 45 | NAC | Northern Air Cargo, LLC. | IATA: NC, Callsign: Yukon, IATA Prefix: 345, ICAO callsign changed from Northern Air Cargo. Name changed from Northern Air Cargo, Inc. | USA | AVCODES |
| 46 | NAC | Northern Air Cargo | IATA: NC | | ICAO1 |
| 47 | NAC | NASHVILLE & ASHLAND CITY RAILROAD CO. | | | PWRC |
| 48 | NACA | NATIONAL CARTAGE CO | | | SCAC3 |
| 49 | NACB | NORTH AMERICAN CARIBBEAN LINE LTD. | | | SCAC3 |
| 50 | NACB | National Coal Board | Real: NCB | GB | TRAFFIC |
| 51 | NACC | NORTH AMERICAN CAR CO. | | | PWRC |
| 52 | NACCO | NACCO SAS | | F | TRAFFIC |
| 53 | NACCO | NACCO GmbH | | DE | VKM |
| 54 | NACD | NORTH AMERICAN CARGO SERVICES INC | | | SCAC4 |
| 55 | NACE | NARROWS CARRIERS INC | | | SCAC3 |
| 56 | NACE | NORTH AMERICAN COMPOSITES DIV OF IN | | | SCAC4 |
| 57 | NACG | NATIONAL AIR CARGO GROUP INC | | | SCAC4 |
| 58 | NACH | NA-CHURS TRANSPORTATION INC | | | SCAC3 |
| 59 | NACI | NACAL, INC | | | SCAC3 |
| 60 | NACI | NACAL INC | | | SCAC4 |
| 61 | NACJ | NATIONAL CARGO INC | | | SCAC3 |
| 62 | NACK | N & C KOHLIG INC | | | SCAC3 |
| 63 | NACL | NACKE, CLETUS TRUCK LINE INC | | | SCAC3 |
| 64 | NACM | NORTH AMERICAN COMPENDIUMS LTD | | | SCAC4 |
| 65 | NACO | NATICK CITGO | | | SCAC3 |
| 66 | NACP | NORTH AMERICAN CARRIERS | | | SCAC4 |
| 67 | NACQ | NATIONAL AIR CARGO INC | | | SCAC4 |
| 68 | NACR | Nashville & Ashland City R.R. | added 1/1982; eliminated 10/1987; eliminated 7/1989; 1/1994-7/2005 | | NAKINA |
| 69 | NACR | Nashville & Ashland City R.R. | added 1/82; eliminated 10/87; eliminated 7/89; 1/94-7/2000 | | NRHS |
| 70 | NACR | NASHVILLE & ASHLAND CITY RAILROAD | | | PWRC |
| 71 | NACR | Nashville and Ashland City Railroad | | | RSRV |
| 72 | NACR | NASHVILLE & ASHLAND CITY RAILROAD | | | SCAC3 |
| 73 | NACS | NATIONAL COURIER SYSTEMS INC | | | SCAC3 |
| 74 | NACS | NEW ACTIVITY SHIPPING INC | | | SCAC4 |
| 75 | NACT | NATIONAL CITY TRANSFER & STORAGE | | | SCAC3 |
| 76 | NACT | NATIONAL CITY TRANSFER & STORAGE | | | SCAC4 |
| 77 | NACU | NALCO LIMITED | | | SCAC4 |
| 78 | NACV | NOBLE AMERICAS CORP | | | SCAC4 |
| 79 | NACW | NATIONAL COACH WORKS INC | | | SCAC3 |
| 80 | NACX | General Electric Rail Services Corp. | added 1/2000; 7/2000-7/2005 | | NAKINA |
| 81 | NACX | North American Chemical Co. | added 4/1991; eliminated 10/1991 | | NAKINA |
| 82 | NACX | General Electric Railcar Services Corp. | added 10/1991; 1/1994; eliminated 1/2000 | | NAKINA |
| 83 | NACX | North American Car Corp. | added 1/1976; eliminated 10/1979 | | NAKINA |
| 84 | NACX | Hooker Chemical Corp. | 4/1970; eliminated 4/1971 | | NAKINA |
| 85 | NACX | Niagara Alkali Co. (Hooker Chemical Corp.) | 10/1966 | | NAKINA |
| 86 | NACX | Hooker Chemical Corp. | added 10/1958; 4/1961-7/1965 | | NAKINA |
| 87 | NACX | Hooker Electrochemical Co. | 10/1957; eliminated 10/1958 | | NAKINA |
| 88 | NACX | Hooker Chemical Corp. | added 7/1956 | | NAKINA |
| 89 | NACX | Niagara Alkali Co. | 8/1920-7/1954; eliminated 7/1956 | | NAKINA |
| 90 | NACX | Niagara Alkali Co. | 4/38-1/52; eliminated 7/56 | | NRHS |
| 91 | NACX | Hooker Chemical Corp. | added 7/56 | | NRHS |
| 92 | NACX | Hooker Electrochemical Co. | 10/57; eliminated 10/58 | | NRHS |
| 93 | NACX | Hooker Chemical Corp. | added 10/58; 4/61-7/65 | | NRHS |
| 94 | NACX | Niagara Alkali Co. (Hooker Chemical Corp.) | Oct-66 | | NRHS |
| 95 | NACX | Hooker Chemical Corp. | 4/70; eliminated 4/71 | | NRHS |
| 96 | NACX | North American Chemical Co. | added 4/91; eliminated 10/91 | | NRHS |
| 97 | NACX | General Electric Railcar Services Corp. | added 10/91; 1/94; eliminated 1/2000 | | NRHS |
| 98 | NACX | General Electric Rail Services Corp. | added 1/2000; 7/2000 | | NRHS |
| 99 | NACX | *HOOKER CHEMICAL CORP. [NIAGARA ALKALI CO.] | | | PWRC |
| 100 | NACX | +(NATX) GENERAL ELECTRIC RAIL SERVICES CORPORATION | | | PWRC |
