| 5001 | NPTX | Newport Steel Corp. | added 10/1996; 7/2000; eliminated 4/2003; 7/2005 (not listed) | | NAKINA |
| 5002 | NPTX | Newport Steel Corp. | added 10/96; 7/2000 | | NRHS |
| 5003 | NPTX | NEWPORT STEEL CORPORATION | | | PWRC |
| 5004 | NPTX | Newport Steel Corporation | | | RSRV |
| 5005 | NPTY | NP TRANSPORTATION INC | | | SCAC4 |
| 5006 | NPUI | NEPTUNE LINES INC | | | SCAC4 |
| 5007 | NPUL | NEPTUNE LINES INT'L S.A | | | SCAC3 |
| 5008 | NPUN | NEPTUNIA INCORPORATED | | | SCAC3 |
| 5009 | NPW | National Power Rail | | GB | TRAFFIC |
| 5010 | NPWH | NORTHPOINT WAREHOUSE TRUCKING | | | SCAC3 |
| 5011 | NPWQ | NEPTUNE WORLD WIDE MOVING (VA INC) | | | SCAC3 |
| 5012 | NPWU | BOLUDA LINES S.A | | E | BIC |
| 5013 | NPX | Northeast Aviation, Inc. | Callsign: Northeast Express, | USA | AVCODES |
| 5014 | NPX | Northeast Aviation | | | ICAO1 |
| 5015 | NPX | Northern Petroleum Co. | 8/1920 | | NAKINA |
| 5016 | NPX | NORTHERN PETROLEUM CO. | | | PWRC |
| 5017 | NPXS | NATIONAL PRIORITY EXPRESS INC | | | SCAC3 |
| 5018 | NPXS | N P EXPRESS | | | SCAC4 |
| 5019 | NPYA | NIPAYIA MARITIME COMPANY LIMITED, P | | | SCAC3 |
| 5020 | NPZ | NEVAMAR PLASTIC | | | PWRC |
| 5021 | NPZD | NAPZ DRAYAGE, LTD | | | SCAC3 |
| 5022 | NPZU | JSC MOZYR OR | | BY | BIC |
| 5023 | NQ | Air Japan Company Ltd. | ICAO: AJX, Callsign: Air Japan, Name changed from World Air Network Co., Ltd. ICAO designator changed from WAC. ICAO callsign changed from Wing Ace | J | AVCODES |
| 5024 | NQ | New Zealand Ministry of Transport | Callsign: Civair, | NZ | AVCODES |
| 5025 | NQ | NW Territoral Airways | ICAO: NWT, Bought and merged into First Air during 1997. | CDN | AVCODES |
| 5026 | NQBC | NINE ZERO FOUR EIGHT-ZERO EIGHT FOU | | | SCAC4 |
| 5027 | NQCD | NORQUAY COLONY LTD | | | SCAC4 |
| 5028 | NQCN | NINE ONE ZERO TWO-FOUR NINE SIX EIG | | | SCAC4 |
| 5029 | NQEF | N E F | | | SCAC4 |
| 5030 | NQIC | NINE ONE SIX ZERO-THREE SEVEN FOUR | | | SCAC4 |
| 5031 | NQMC | NIKI MARINE COMPANY INC PIRAEUS GR | | | SCAC3 |
| 5032 | NQN | Transportes Aereos Neuquen Sociedad Anonima | IATA: T8, Callsign: Taneu, Ceased operations. Name changed from Transportes Aereos Neuquen Sociedad del Estado | RA | AVCODES |
| 5033 | NQN | Transportes Aereos Neuquen Sociedad del Estado | IATA: T8, Callsign: Taneu, Name changed to Transportes Aereos Neuquen Sociedad Anonima | RA | AVCODES |
| 5034 | NQN | Grupo LASA S.r.l. | Callsign: Lasa, | RA | AVCODES |
| 5035 | NQOR | NOR TRANSPORTATION SERVICE INC | | | SCAC4 |
| 5036 | NQPS | NORTHWEST PETROLEUM SERVICES | | | SCAC4 |
| 5037 | NQSC | NARCISSUS SHIPPING CORPORATION | | | SCAC3 |
| 5038 | NQSH | NETWORK SHIPPING LTD (A LIBERIAN COMPANY) | | | SCAC3 |
| 5039 | NQSH | NETWORK SHIPPING LTD (A LIBERIAN CO | | | SCAC4 |
| 5040 | NQTI | NTI | | | SCAC4 |
| 5041 | NQTL | NORTHERN QUEBECK TRANSPORT LTD | | | SCAC3 |
| 5042 | NQTS | NTS LLC | | | SCAC4 |
| 5043 | NQWD | NEWTRADE CORP ATHENS GREECE | | | SCAC3 |
| 5044 | NQWT | NEW WORLD TRADE TRANSPORTS INC | | | SCAC4 |
| 5045 | NR | Pamir Air | ICAO: PIR, Callsign: Pamir, Designator NR* reinstated by IATA | AFG | AVCODES |
| 5046 | NR | RUSS JSC Air Transport Co. | ICAO: RUR, Callsign: Angara, IATA Prefix: 437, | RUS | AVCODES |
| 5047 | NR | NorOntair | ICAO: NOT, Callsign: Norontair, | CDN | AVCODES |
| 5048 | NR | Executive Aviation Services Limited | ICAO: ESY, Callsign: Exco Air, Designator NR recalled by IATA. | WAN | AVCODES |
| 5049 | NR | CSE Aviation Ltd. | ICAO: CSE, Callsign: Wigwam, Desigantor NR recalled by IATA | GB | AVCODES |
| 5050 | NR | Max Air Limited | ICAO: NGL, Callsign: Maxair Nigeria, Founded in 2008. Ceased operations | WAN | AVCODES |
| 5051 | NR | Al-Naser Airlines | ICAO: MHK, Callsign: Al-Naser, IATA designator changed to NG. Designator 6N recalled by IATA | IRQ | AVCODES |
| 5052 | NR | Manta Aviation Pvt. Ltd. | ICAO: MAV, Callsign: Sea Wing, Commenced operations on 24 February 2019. | MV | AVCODES |
| 5053 | NR | NEW RIVER RAILWAY CO. | | | PWRC |
| 5054 | NR | NetRail AB | 1995 - | S | svenska-lok.se |
| 5055 | NR | National Rail Corporation | | AUS | TRAFFIC |
| 5056 | NR | NetRail AB | | SE | VKM |
| 5057 | NR&PCCCo. | New River & Pocahontas Consolidated Coal Co. (changed to NRBX) | 7/1935 | | NAKINA |
| 5058 | NRA | Nitra Air | Callsign: Nitra Air, | SK | AVCODES |
| 5059 | NRA | Santi Airlines Limited | Callsign: Santi Airlines, | WAG | AVCODES |
| 5060 | NRA | Noar Linhas Aereas | Callsign: Airnoar, Founded in 2009. Commenced operations in 2010. Ceased operations 20 September 2011. | BR | AVCODES |
| 5061 | NRAC | NIAGARA RACE CRAFTERS INC | | | SCAC4 |
| 5062 | NRAD | NATIONAL ROUTING AND DISTRIBUTION I | | | SCAC4 |
| 5063 | NRAF | NORAM FORWARDING INC | | | SCAC3 |
| 5064 | NRAIL | Northrail GmbH | | DE | VKM |
| 5065 | NRAO | NATIONAL RADIO ASTRONOMY OBSERVATORY | | | PWRC |
| 5066 | NRAO | NORTHERN REFRIGERATED TRANSPORTATIO | | | SCAC4 |
| 5067 | NRAT | NORTH AMERICAN TRANSPORT COMPANY IN | | | SCAC3 |
| 5068 | NRAU | AEROGAS PROCESSORS LIMITED | | TT | BIC |
| 5069 | NRAW | NORTHLAND CARRIERS INC | | | SCAC4 |
| 5070 | NRAX | Newell Recycling of Atlanta Inc. | 7/2005 (not listed) | | NAKINA |
| 5071 | NRAX | NEWELL RECYCLING OF ATLANTA, INC. | | | PWRC |
| 5072 | NRAX | NEWELL RECYCLING OF ATLANTA INC | | | SCAC4 |
| 5073 | NRBK | NORBROOK INDUSTRIES LTD | | | SCAC4 |
| 5074 | NRBN | NORTH-BOUND TRANSPORTATION | | | SCAC3 |
| 5075 | NRBO | NOR-BON OIL CO | | | SCAC3 |
| 5076 | NRBX | Fruit Growers Express Co. | added 7/1999; 7/2000-7/2005 | | NAKINA |
| 5077 | NRBX | Merchants Despatch Transportation Corp. | added 7/1962; 7/1965-1/1994; eliminated 7/1999 | | NAKINA |
| 5078 | NRBX | Northern Refrigerator Line, Inc. | added 10/1958; 4/1961; eliminated 7/1962 | | NAKINA |
| 5079 | NRBX | New River & Pocahontas Consolidated Coal Co. (previously N.R.&P.C.C.Co.) | added 11/1934; 7/1935-7/1954; eliminated 7/1957 | | NAKINA |
| 5080 | NRBX | New River & Pocahontas Consolidated Coal Co. | 4/38-1/52 | | NRHS |
| 5081 | NRBX | Northern Refrigerator Line | added 10/58; 4/61 | | NRHS |
| 5082 | NRBX | Merchants Despatch Transportation Corp. | 7/65-1/94; eliminated 7/99 | | NRHS |
| 5083 | NRBX | Fruit Growers Express Co. | added 7/99; 7/2000 | | NRHS |
| 5084 | NRBX | *NEW RIVER & POCAHONTAS CONSOLIDATED COAL CO. [N.R. & P.C.C. CO.] | | | PWRC |
| 5085 | NRBX | *(MDTX) MERCHANTS DESPATCH TRANS. CORP. | | | PWRC |
| 5086 | NRBX | +FRUIT GROWERS EXPRESS [NORTHERN REFRIGERATOR LINE] | | | PWRC |
| 5087 | NRBX | Fruit Growers Express (Merchants Despatch Transportation Corporation) | | | RSRV |
| 5088 | NRBX | FRUIT GROWERS EXPRESS COMPANY | | | SCAC4 |
| 5089 | NRC | North Sea Airways | Callsign: North Sea, Ceased operations. | NL | AVCODES |
| 5090 | NRC | North Sea Airways | | | ICAO1 |
| 5091 | NRC | Merchants Despatch Transportation Corp. | added 7/1962; 7/1965-1/1980; eliminated 1/1983 | | NAKINA |
| 5092 | NRC | Northern Refrigerator Line, Inc. | 7/1937-4/1961; eliminated 7/1962 | | NAKINA |
| 5093 | NRC | Northern Refrigerator Car Co. (Northern Refrigerator Line, Inc.) | 7/1935 | | NAKINA |
| 5094 | NRC | Northern Refrigerator Line, Inc. | 4/38-4/61 | | NRHS |
| 5095 | NRC | Merchants Despatch Transportation Corp. | 7/65-1/80; eliminated 1/83 | | NRHS |
| 5096 | NRC | MERCHANTS DESPATCH TRANS. CORP. [NORTHERN REFRIGERATOR LINE INC] | | | PWRC |
| 5097 | NRC | National Refrigerator Car Line (Merchants Despatch Transportation Corporation) | | | RSRV |
| 5098 | NRC | Nigerian Railway Corporation | | WAN | TRAFFIC |
| 5099 | NRCB | NORTH CARIBBEAN TRANSPORT INC | | | SCAC4 |
| 5100 | NRCC | NOR-CAL TRANSPORLTAITON | | | SCAC3 |
