| 1 | NP | Skytrans | Designator NP* recalled by IATA | AUS | AVCODES |
| 2 | NP | Heavylift Cargo Airlines Ltd. | ICAO: HLA, Callsign: Heavylift, Name changed to HC Airlines Ltd. ICAO callsign changed from November Papa | GB | AVCODES |
| 3 | NP | Heavylift Cargo Airlines Ltd. | ICAO: HLA, Callsign: November Papa, ICAO callsign changed to Heavylift | GB | AVCODES |
| 4 | NP | Nile Air | ICAO: NIA, Callsign: Hapi Air, ICAO callsign changed to Nile Bird | ET | AVCODES |
| 5 | NP | Nile Air | ICAO: NIA, Callsign: Nile Bird, ICAO callsign changed from Hapi Air | ET | AVCODES |
| 6 | NP | BNSF Ry. Co. | added 4/2005; 7/2005 | | NAKINA |
| 7 | NP | Burlington Northern Santa Fe Ry. Co. | 7/2000; eliminated 4/2005 | | NAKINA |
| 8 | NP | Burlington Northern R.R. Co. | added 7/1981; 1/1994 | | NAKINA |
| 9 | NP | Burlington Northern Inc. | 1/1975-1/1980; eliminated 7/1981 | | NAKINA |
| 10 | NP | Northern Pacific Ry. Co. | 1/1941-10/1966 | | NAKINA |
| 11 | NP | Northern Pacific Ry. Co. | 1/52-10/66 | | NRHS |
| 12 | NP | Burlington Northern Inc. | 1/75-1/80; eliminated 7/81 | | NRHS |
| 13 | NP | Burlington Northern R.R. Co. | added 7/81; 1/94 | | NRHS |
| 14 | NP | Burlington Northern Santa Fe Ry. Co. | Jul-00 | | NRHS |
| 15 | NP | BNSF RWY. [BURLINGTON NORTHERN & SANTA FE; BURLINGTON NORTHERN RR; NORTHERN PACIFIC RY] | | | PWRC |
| 16 | NP | Northern Pacific Railway (BNSF Railway) | | | RSRV |
| 17 | NP | Northern Pacific | | USA | TRAFFIC |
| 18 | NPAD | NPA DE MEXICO SA DE CV | | | SCAC4 |
| 19 | NPAL | NOPAL CARIBE,DIV.OF NORTHERN PAN-AM LINES,A/S | | | PWRC |
| 20 | NPAL | NEGRETE PADILLA, ANGELICA LETICIA, | | | SCAC4 |
| 21 | NPAP | NETWORK PAPER AND PACKAGING LTD | | | SCAC4 |
| 22 | NPAT | NAPA TRANSPORTATION INC | | | SCAC3 |
| 23 | NPAT | NAPA TRANSPORTATION INC | | | SCAC4 |
| 24 | NPB | Norfolk and Portsmouth Belt Line R.R. Co. | 1/1975-7/2005; eliminated 7/2009 | | NAKINA |
| 25 | NPB | (N&PB) Norfolk and Portsmouth Belt Line R.R. Co. | 4/1970 | | NAKINA |
| 26 | NPB | (N&PB) Norfolk and Portsmouth Belt Line R.R. Co. | Apr-70 | | NRHS |
| 27 | NPB | Norfolk and Portsmouth Belt Line R.R. Co. | 1/75-7/2000 | | NRHS |
| 28 | NPB | NORFOLK & PORTSMOUTH BELT LINE RAILROAD | | | PWRC |
| 29 | NPB | Norfolk and Portsmouth Belt Line Railroad | | | RSRV |
| 30 | NPB | NORFOLK & PORTSMOUTH BELT LINE RAIL | | | SCAC4 |
| 31 | NPBS | NATIONAL PIGGYBACK SERVICES INC | | | SCAC3 |
| 32 | NPC | Western Air Couriers, Inc. | Callsign: Norpac, | USA | AVCODES |
| 33 | NPC | Western Air Couriers | | | ICAO1 |
| 34 | NPCC | NORTHPORT CORPORATION OF ST CLOUD | | | SCAC4 |
| 35 | NPCF | NORTH PACIFIC COAST FREIGHT BUREAU | | | SCAC3 |
| 36 | NPCL | NORTH PACIFIC CARRIERS LTD | | | SCAC3 |
| 37 | NPCN | NEWPORT CONTAINER LINE INC | | | SCAC4 |
| 38 | NPCO | NORTHEASTERN PRODUCTS CORP | | | SCAC3 |
| 39 | NPCT | NORTHERN POULTRY COMPANY, THE | | | SCAC4 |
| 40 | NPCU | NEWPORT TANK CONTAINERS (USA) LLC | | USA | BIC |
| 41 | NPCU | Newport Tank Containers | | | RSRV |
| 42 | NPCU | NAVIERA PASCHOLD, S.A. | | | SCAC3 |
| 43 | NPCU | NEWPORT TANK CONTAINERS INC | | | SCAC4 |
| 44 | NPCW | NPC | | | SCAC4 |
| 45 | NPCX | Equistar Chemicals, LP | added 4/1998; 7/2000-7/2005 | | NAKINA |
| 46 | NPCX | Quantum Chemical Corp., USI Division | added 7/1988; 1/1994; eliminated 4/1998 | | NAKINA |
| 47 | NPCX | USI Chemicals Co., Division of National Distillers & Chemical Corp. | added 7/1987; eliminated 7/1988 | | NAKINA |
| 48 | NPCX | U.S. Industrial Chemicals Co., Division of National Distillers and Chemical Corp. | eliminated 7/1987 | | NAKINA |
| 49 | NPCX | Enron Chemical Co. | added 10/1986; eliminated 4/1987 | | NAKINA |
| 50 | NPCX | USI Chemicals Co., Inc. | added 4/1987 | | NAKINA |
| 51 | NPCX | NORCHEM, Inc. | added 1/1986; eliminated 10/1986 | | NAKINA |
| 52 | NPCX | NORCHEM | added 7/1985; eliminated 1/1986 | | NAKINA |
| 53 | NPCX | Northern Petrochemical Co. | added 1/1975; 1/1975-1/1980; eliminated 7/1985 | | NAKINA |
| 54 | NPCX | National Beef Packing Co. | added 10/1968; eliminated 7/1969 | | NAKINA |
| 55 | NPCX | National Packing Co., Inc. | added 7/1967; eliminated 10/1968 | | NAKINA |
| 56 | NPCX | National Car Co. | 1/1946-1/1950 | | NAKINA |
| 57 | NPCX | National Pole Co. | 8/1920-7/1923 | | NAKINA |
| 58 | NPCX | National Packing Co., Inc. | added 7/67; eliminated 10/68 | | NRHS |
| 59 | NPCX | National Beef Packing Co. | added 10/68; eliminated 7/69 | | NRHS |
| 60 | NPCX | Northern Petrochemical Co. | added 1/75; 1/75-1/80 | | NRHS |
| 61 | NPCX | NORCHEM | eliminated 1/86 | | NRHS |
| 62 | NPCX | NORCHEM, Inc. | added 1/86; eliminated 10/86 | | NRHS |
| 63 | NPCX | Enron Chemical Co. | added 10/86; eliminated 4/87 | | NRHS |
| 64 | NPCX | USI Chemicals Co., Inc. | added 4/87 | | NRHS |
| 65 | NPCX | U.S. Industrial Chemicals Co., Division of National Distillers and Chemical Corp. | eliminated 7/87 | | NRHS |
| 66 | NPCX | USI Chemicals Co., Division of National Distillers & Chemical Corp. | added 7/87; eliminated 7/88 | | NRHS |
| 67 | NPCX | Quantum Chemical Corp., USI Division | added 7/88; 1/94; eliminated 4/98 | | NRHS |
| 68 | NPCX | Equistar Chemicals, LP | added 4/98; 7/2000 | | NRHS |
| 69 | NPCX | *NATIONAL POLE CO. | | | PWRC |
| 70 | NPCX | *NATIONAL CAR CO. | | | PWRC |
| 71 | NPCX | *NATIONAL BEEF PACKING CO. [NATIONAL PACKING CO.] | | | PWRC |
| 72 | NPCX | +EQUISTAR CHEMICALS, LP [(USIX) QUANTUM CHEMICAL CORPORATION, USI DIV.; ENRON CHEMICAL CO.; NORCHEM, INMC.; NORTHERN PETROCHEMICAL} | | | PWRC |
| 73 | NPCX | Northern Petrochemical (Equistar Chemicals) | | | RSRV |
| 74 | NPCX | EQUISTAR CHEMICALS LP | | | SCAC4 |
| 75 | NPDE | NEELY TRUCKING INC | | | SCAC3 |
| 76 | NPDF | NEWPARK DRILLING FLUIDS | | | SCAC4 |
| 77 | NPDG | Neue Pellwormer Dampfschiffahrts GmbH | | D | TRAFFIC |
| 78 | NPDI | NPDI INC | | | SCAC3 |
| 79 | NPDN | NORTHERN PLAINS DISTRIBUTING INC | | | SCAC4 |
| 80 | NPDR | NAPA DRAYAGE | | | SCAC3 |
| 81 | NPDU | NEPTUNE PACIFIC DIRECT LINE PTE. LTD. | | SGP | BIC |
| 82 | NPDX | Nickel Plate Refrigerator Despatch | 7/1923-7/1932 | | NAKINA |
| 83 | NPDX | NICKEL PLATE REFRIGERATOR DESPATCH | | | PWRC |
| 84 | NPDZ | N. P. DRAIN | | | PWRC |
| 85 | NPEC | NCD PACKAGE EXPRESS INC | | | SCAC4 |
| 86 | NPEE | NPE INC | | | SCAC4 |
| 87 | NPEI | NANAS PETROLEUM INC | | | SCAC3 |
| 88 | NPEQ | NATIONAL PRIDE EQUIPMENT | | | SCAC4 |
| 89 | NPET | NPE TRANS | | | SCAC3 |
| 90 | NPET | NICKEY PETROLEUM | | | SCAC4 |
| 91 | NPEX | National Petroleum Corp. | 7/1923 | | NAKINA |
| 92 | NPEX | NATIONAL PETROLEUM CORP. | | | PWRC |
| 93 | NPFI | NORTHERN PRIDE FREIGHT INC | | | SCAC4 |
| 94 | NPFL | NORTH PACIFIC FREIGHT LINES INC | | | SCAC3 |
| 95 | NPFU | BOLUDA LINES S.A | | E | BIC |
| 96 | NPG | Supernova Airlines LLC | Callsign: Nova, Owned by Nova Poshta. | UA | AVCODES |
| 97 | NPG | NPG Bau Neuschitzer GmbH & Co KG | | AT | VKM |
| 98 | NPGC | NORTHWEST PROPANE GAS CO | | | SCAC4 |
| 99 | NPGI | NELSON PROPANE GAS INC | | | SCAC4 |
| 100 | NPGS | NONNA PIAS GOURMET SAUCES LTD | | | SCAC4 |
