| 2901 | NHWT | NORTHWEST TRAILER INC | | | SCAC4 |
| 2902 | NHWU | NORFOLK SOUTHERN CORP | | | SCAC4 |
| 2903 | NHX | Noordzee Helikopters Vlaanderen | Callsign: Evo, | B | AVCODES |
| 2904 | NHZ | Nada Air Service | Callsign: Nada Air, | TCH | AVCODES |
| 2905 | NHZ | NHV Helicopters Ltd | Callsign: Gold, | GB | AVCODES |
| 2906 | NHZ | Nada Air Service | | | ICAO1 |
| 2907 | NHZO | NEW HORIZONS INC | | | SCAC3 |
| 2908 | NI | Lineas Aereas Nicaragus, S.A. | Callsign: Lanica, Name changed to Aeronica, Aerolineas Nicaraguenses S.A. | NIC | AVCODES |
| 2909 | NI | Aeronica, Aerolineas Nicaraguenses S.A. | ICAO: ANI, Callsign: Aeronica, Name changed from Lineas Aereas Nicaragus | NIC | AVCODES |
| 2910 | NI&M | New Iberia & Northern R.R. Co. | 4/1938 | | NAKINA |
| 2911 | NI&M | New Iberia & Northern R.R. Co. (Gulf Coast Lines) | 7/1932 | | NAKINA |
| 2912 | NI&M | New Iberia & Northern R.R. Co. | Apr-38 | | NRHS |
| 2913 | NI&M | NEW IBERIA & NORTHERN RAILROAD CO. | | | PWRC |
| 2914 | NI&N | New Iberia & Northern R.R. Co. (Gulf Coast Lines) | 8/1920-7/1936 | | NAKINA |
| 2915 | NI&N | NEW IBERIA & NORTHERN RAILROAD CO. | | | PWRC |
| 2916 | NIA | Nordavia Fluggesellschaft mbH | Callsign: Nordavia, | D | AVCODES |
| 2917 | NIA | Nile Air | IATA: NP, Callsign: Hapi Air, ICAO callsign changed to Nile Bird | ET | AVCODES |
| 2918 | NIA | Nile Air | IATA: NP, Callsign: Nile Bird, ICAO callsign changed from Hapi Air | ET | AVCODES |
| 2919 | NIAC | NIATCO TRUCKING CORP | | | SCAC3 |
| 2920 | NIAG | Niederrheinische Verkehrsbetriebe AG | Moers | D | privat-bahn.de |
| 2921 | NIAG | Niederrheinische Verkehrsbetriebe AG | | D | TRAFFIC |
| 2922 | NIAG | Niederrheinische Verkehrsbetriebe | | DE | VKM |
| 2923 | NIAJ | Consolidated Rail Corp. | 1/1980 | | NAKINA |
| 2924 | NIAJ | Niagara Junction Ry. Co. | 1/1975 | | NAKINA |
| 2925 | NIAJ | Niagara Junction Ry. Co. | Jan-75 | | NRHS |
| 2926 | NIAJ | Consolidated Rail Corp. | Jan-80 | | NRHS |
| 2927 | NIAJ | CONRAIL [NIAGARA JUNCTION RAILWAY] | | | PWRC |
| 2928 | NIAJ | Niagara Junction Railway (Conrail) | | | RSRV |
| 2929 | NIAL | NIAGARA LEASING CORP | | | SCAC3 |
| 2930 | NIAR | NICHOLS & RONK INC | | | SCAC3 |
| 2931 | NIAT | NATIONAL TRANSPORT SERVICES CO INC | | | SCAC3 |
| 2932 | NIAT | NIAGARA TANK LINES INC | | | SCAC4 |
| 2933 | NIAX | Niagara & Western New York R.R. Co., Inc. | 7/2005 (not listed) | | NAKINA |
| 2934 | NIAX | Niacet Chemicals Division, United States Vanadium Corp. | 1/1946-1/1950 | | NAKINA |
| 2935 | NIAX | Niacet Chemicals Corp. | 7/1930-1/1945 | | NAKINA |
| 2936 | NIAX | *NIACET CHEMICALS DIV., US VANADIUM CORP. | | | PWRC |
| 2937 | NIAX | *NIAGARA & WESTERN NEW YORK RAILROAD | | | PWRC |
| 2938 | NIAX | Niagara and Western New York Railroad | | | RSRV |
| 2939 | NIAX | Niagara & Western New York Railroad | | USA | TRAFFIC |
| 2940 | NIBC | NIBCO DE REYNOSA SA DE CV | | | SCAC4 |
| 2941 | NIC | Northern Illinois Commuter | Callsign: Illinois Commuter, | USA | AVCODES |
| 2942 | NIC | Northern Illinois Commuter | | | ICAO1 |
| 2943 | NICA | NICHOLS CAMBRIDGE EXPRESS | | | SCAC3 |
| 2944 | NICC | NICHOLS TRUCKING | | | SCAC3 |
| 2945 | NICD | Northern-Indiana Commuter Transportation District | 1/1994-7/2005 | | NAKINA |
| 2946 | NICD | Northern-Indiana Commuter Transportation District | 1/94-7/2000 | | NRHS |
| 2947 | NICD | NORTHERN INDIANA COMMUTER TRANSPORTATION DISTRICT | | | PWRC |
| 2948 | NICD | South Shore Line (NICTD) | | | RSRV |
| 2949 | NICD | NORTHERN-INDIANA COMMUTER TRANSPORT | | | SCAC3 |
| 2950 | NICD | NORTHERN INDIANA COMMUTER TRANSPORT | | | SCAC4 |
| 2951 | NICD | Northern Indiana Commuter Transportation District | City: Chicago | USA | TRAFFIC |
| 2952 | NICE | NITRO | | | SCAC4 |
| 2953 | NICE | | Real: TN, City: Nice | F | TRAFFIC |
| 2954 | NICEB | Nassau Inter-County Express | Real: NICE | USA | TRAFFIC |
| 2955 | NICF | NICKELS FARM | | | SCAC3 |
| 2956 | NICG | NICKS CARTAGE CO | | | SCAC3 |
| 2957 | NICG | NICU PRO TRUCKING INC | | | SCAC4 |
| 2958 | NICH | NICHOLAS TRANSPORTATION COMPANY | | | SCAC3 |
| 2959 | NICI | NOEL ICE COMPANY INC | | | SCAC3 |
| 2960 | NICI | NINE ZERO FOUR SEVEN-ZERO EIGHT FOU | | | SCAC4 |
| 2961 | NICJ | NICHOLAS, G L TRUCKING INC | | | SCAC3 |
| 2962 | NICK | NICKS TRANSPORT LLC | | | SCAC4 |
| 2963 | NICL | NICE FUEL CO LLC | | | SCAC4 |
| 2964 | NICM | NICHOLSON MOBILE HOME | | | SCAC3 |
| 2965 | NICN | NICOLES TRANSPORTATION | | | SCAC3 |
| 2966 | NICN | NINE ZERO ONE SEVEN-ONE NINE ZERO O | | | SCAC4 |
| 2967 | NICO | NICO SHIPPING CORP | | | SCAC4 |
| 2968 | NICQ | NICKELS TRUCKING CO | | | SCAC3 |
| 2969 | NICQ | N I C INDUSTRIES INC | | | SCAC4 |
| 2970 | NICR | NICHOLAS TRANSPORT INC | | | SCAC4 |
| 2971 | NICS | NICOS EXPRESS INC | | | SCAC4 |
| 2972 | NICU | NIC LEASING INC | | | PWRC |
| 2973 | NICU | NIC Leasing | | | RSRV |
| 2974 | NICU | NIC LEASING | | | SCAC3 |
| 2975 | NICV | NIC TRAVEL | | | SCAC3 |
| 2976 | NICV | NICOLET TRANSPORTATION SERVICE LLC | | | SCAC4 |
| 2977 | NICX | Niagara & Western New York R.R. Co., Inc. | 7/2005 (not listed) | | NAKINA |
| 2978 | NICX | *NIAGARA & WESTERN NEW YORK RAILROAD | | | PWRC |
| 2979 | NICX | *NILES CANYON RAILWAY | | | PWRC |
| 2980 | NICX | Niles Canyon Railway | | | RSRV |
| 2981 | NICZ | NORTHWEST IOWA COOP | | | PWRC |
| 2982 | NID | Aeroni, S.A. de C.V. | Callsign: Aeroni, | MEX | AVCODES |
| 2983 | NID | Aeroni | | | ICAO1 |
| 2984 | NIDA | NORTH IDAHO SHUTTLE SERVICE INC | | | SCAC3 |
| 2985 | NIDA | Kleinbahn Niebüll-Dagebüll | | D | TRAFFIC |
| 2986 | NIDE | NICHOLSON, DALE E | | | SCAC3 |
| 2987 | NIDF | NIEDFELDT TRUCKING SERVICE INC | | | SCAC3 |
| 2988 | NIDH | NORTH IDAHO FREIGHT | | | SCAC3 |
| 2989 | NIDI | NICHOLS, DON INC | | | SCAC3 |
| 2990 | NIDM | NISSIN INTERNATIONAL DE MEXICO S A | | | SCAC4 |
| 2991 | NIDS | NATIONAL INSTRUMENT DISTRIBUTORS IN | | | SCAC3 |
| 2992 | NIDT | NIELSEN, D TRUCKING | | | SCAC3 |
| 2993 | NIDU | HAPAG LLOYD A.G | | D | BIC |
| 2994 | NIDU | NILE DUTCH AFRICA LINE | | | SCAC4 |
| 2995 | NIE | Aeroejecutiva Nieto, S.A. de C.V. | Callsign: Aeronieto, | MEX | AVCODES |
| 2996 | NIE | Aeroejecutiva Nieto | | | ICAO1 |
| 2997 | NIEC | NIERMANN CARTAGE COMPANY | | | SCAC3 |
| 2998 | NIED | NIEDERGERKE TRUCK LINE, INCORPORATE | | | SCAC3 |
| 2999 | NIEE | NIEMIEC EXPRESS | | | SCAC3 |
| 3000 | NIEE | NIEB, E SERVICES INCORPORATED | | | SCAC4 |
