| 3201 | NITRO | Zakłady Chemiczne “NITRO-CHEM” S.A. | | PL | VKM |
| 3202 | NITS | NIEDERBRACH TRUCK SERVICE, INC | | | SCAC3 |
| 3203 | NITU | LLC NUNIT | | UA | BIC |
| 3204 | NITX | Nitram Inc. | added 7/1979; 1/1980-1/1994; eliminated 1/1995; added 10/1996; eliminated 1/1997 | | NAKINA |
| 3205 | NITX | Nitram Inc. | added 7/79; 1/80-1/94; eliminated 1/95; added 10/96; eliminated 1/97 | | NRHS |
| 3206 | NITX | NITRAM, INC. | | | PWRC |
| 3207 | NITX | Nitram | | | RSRV |
| 3208 | NITX | VIRGINIA INTERNATIONAL TERMINALS IN | | | SCAC4 |
| 3209 | NITZ | NORFOLK INTERNATIONAL TERMINAL | | | PWRC |
| 3210 | NIU | Coral Air Ltd. | Callsign: Niue, | NZ | AVCODES |
| 3211 | NIVC | NIVRAM CORP | | | SCAC3 |
| 3212 | NIVS | NILSON VAN & STORAGE | | | SCAC3 |
| 3213 | NIVS | NILSON VAN & STORAGE | | | SCAC4 |
| 3214 | NIVX | Nivco, Corp. | added 1/1967; 4/1970-1/1975; eliminated 7/1975 | | NAKINA |
| 3215 | NIVX | Nivco, Corp. | added 1/67; 4/70-1/75; eliminated 7/75 | | NRHS |
| 3216 | NIVX | NIVCO, CORP. | | | PWRC |
| 3217 | NIWA | NIEKAMP, WILLIAM A TRUCK SERVICE | | | SCAC3 |
| 3218 | NIWA | NIEKAMP, WILLIAM A TRUCK SERVICE IN | | | SCAC4 |
| 3219 | NIWX | Northern Illinois & Wisconsin Ry. Corp. | 7/2000-7/2005 (not listed) | | NAKINA |
| 3220 | NIWX | Northern Illinois & Wisconsin Ry. Corp. | Jul-00 | | NRHS |
| 3221 | NIWX | NORTHERN ILLINOIS & WISCONSIN RWY. CORP. | | | PWRC |
| 3222 | NIWX | Northern Illinois and Wisconsin Railway | | | RSRV |
| 3223 | NIWX | NORTHERN ILLINOIS & WISCONSIN RAILW | | | SCAC4 |
| 3224 | NIXA | NIXA TRUCKING INC | | | SCAC4 |
| 3225 | NIXI | NIXON TRANSPORTATION INC | | | SCAC3 |
| 3226 | NIXN | NIXON FREIGHT LINES | | | SCAC3 |
| 3227 | NIXT | NIX TRANSPORTATION INC | | | SCAC3 |
| 3228 | NIXT | NIX TRUCKING | | | SCAC4 |
| 3229 | NIZ | NALLEYS INC. | | | PWRC |
| 3230 | NJ | Vanguard Airlines, Inc. | ICAO: VGD, Callsign: Vanguard Air, IATA Prefix: 311, Filed for Chapter 11 and suspended all operations on 30 July 2002. Designator NJ reinstated by IATA | USA | AVCODES |
| 3231 | NJ | Nordisk Aviation Products, Inc. | | USA | AVCODES |
| 3232 | NJ | Aero VIP, S.A. | ICAO: AOG, Callsign: Avip, IATA Prefix: 592, Established on 15 March 1999. Commenced operations on 23 June 1999. Ceased operations in November 2010. | RA | AVCODES |
| 3233 | NJ | Nordic Global Airlines Oy | ICAO: NGB, Callsign: Nordic Global, Founded on 11 April 2011. Ceased opeation on 31 May 2015. Subsidiary of Finnair Group and Neff Capital Management. | FIN | AVCODES |
| 3234 | NJ | Niger Airways SA | Designator NJ recalled by IATA. | RN | AVCODES |
| 3235 | NJ | Romcargo Airlines S.r.l. | ICAO: RCR, Callsign: Romcargo, IATA Prefix: 690, Name changed from Fly Sky. ICAO designator changed from FSG. | RO | AVCODES |
| 3236 | NJ | Nordjyske Jernbaner A/S | 2001 - | DK | jernbanen.dk |
| 3237 | NJ | Delaware and Hudson Ry. Co., Inc. | added 7/1994; 7/2000-7/2005 | | NAKINA |
| 3238 | NJ | CP Rail | added 7/1992; 1/1994; eliminated 7/1994 | | NAKINA |
| 3239 | NJ | Napierville Junction Ry. Co. | 1/1975-1/1980; eliminated 7/1992 | | NAKINA |
| 3240 | NJ | Niagara Junction Ry. Co. | 4/1938-1/1941 | | NAKINA |
| 3241 | NJ | Niagara Junction Ry. Co. | Apr-38 | | NRHS |
| 3242 | NJ | Napierville Junction Ry. Co. | 1/75-1/80; eliminated 7/92 | | NRHS |
| 3243 | NJ | CP Rail | added 7/92; 1/94; eliminated 7/94 | | NRHS |
| 3244 | NJ | Delaware and Hudson Ry. Co., Inc. | added 7/94; 7/2000 | | NRHS |
| 3245 | NJ | CP RAIL (CANADIAN PACIFIC) [DELAWARE AND HUDSON RWY; NAPIERVILLE JUNCTION RY.; NIAGARA JUNCTION RY.] | | | PWRC |
| 3246 | NJ | Niagara Junction Railway (Canadian Pacific Railway) | | | RSRV |
| 3247 | NJ | Napierville Junction Ry. Co. | | CDN | TRAFFIC |
| 3248 | NJ | Nässjö Järnvägsmuseum | | SE | VKM |
| 3249 | NJA | Sky Air Cargo Services (UK) Ltd. | Formerly Tranway Air Interbational Ltd. | GB | AVCODES |
| 3250 | NJA | New Japan Aviation Co., Ltd. | Callsign: Shin Nihon, | J | AVCODES |
| 3251 | NJA | New Japan Aviation | | J | TRAFFIC |
| 3252 | NJAC | NANJAC TRANSPORTATION SERVICES LTD | | | SCAC3 |
| 3253 | NJAC | N JOSHI TRANSPORT | | | SCAC4 |
| 3254 | NJAQ | N J AMERICAN WHSE CORP | | | SCAC3 |
| 3255 | NJAR | NORTH JERSEY AIR SERVICE INC | | | SCAC3 |
| 3256 | NJBU | CS EURASIA LEASING (SEA) PTE LTD | | SGP | BIC |
| 3257 | NJBW | NICE JEWISH BOY WITH WAREHOUSE INC | | | SCAC3 |
| 3258 | NJC | Nashville Jet Charters, Inc. | Callsign: Nashville Jet, | USA | AVCODES |
| 3259 | NJC | Nashville Jet Charters | | | ICAO1 |
| 3260 | NJCC | NEW JERSEY CHARCOAL CO | | | SCAC3 |
| 3261 | NJCI | NEW JERSEY CARTAGE CO INC | | | SCAC3 |
| 3262 | NJCT | NEW JERSEY COAST TRANSFER COMPANY | | | SCAC3 |
| 3263 | NJCT | North Jersey Commuter Transportation | City: New Jersey | USA | TRAFFIC |
| 3264 | NJCU | NINGBO JINSHI CONTAINERS CO., LTD. | | PRC | BIC |
| 3265 | NJCX | New Jersey Rail Carrier | | | RSRV |
| 3266 | NJD | Norsk Jernbanedrift AS | | NO | VKM |
| 3267 | NJDE | NJ DRIVERS EXPRESS CORP | | | SCAC4 |
| 3268 | NJDK | Nordjyske Jernbaner A/S | 2001 - | DK | TRAFFIC |
| 3269 | NJDOT | New Jersey DOT | | USA | TRAFFIC |
| 3270 | NJDT | NJD TRANSPORT LLC | | | SCAC4 |
| 3271 | NJDX | North American Car Corp. | added 4/1956; 10/1957-1/1975; eliminated 10/1979; 1/1980 | | NAKINA |
| 3272 | NJDX | North American Car Corp. | 10/57-1/80 | | NRHS |
| 3273 | NJDX | GE RAIL SERVICES {NORTH AMERICAN CAR CORP.} | | | PWRC |
| 3274 | NJDX | GE Rail Services | | | RSRV |
| 3275 | NJE | Netjets, Transportes Aereos, S.A. | Callsign: Skyshare, ICAO callsign changed to Fraction | P | AVCODES |
| 3276 | NJE | Netjets, Transportes Aereos, S.A. | Callsign: Fraction, ICAO callsign changed from Skyshare | P | AVCODES |
| 3277 | NJEC | NEW JERSEY EXPRESS CORP | | | SCAC3 |
| 3278 | NJEC | NORTH JERSEY ENERGY CORP | | | SCAC4 |
| 3279 | NJEI | NUTT, JOSEPH E & SON INC | | | SCAC3 |
| 3280 | NJEL | NINGBO JET EXPRESS INTL FREIGHT FWD | | | SCAC4 |
| 3281 | NJEN | N J ENTERPRISES LTD | | | SCAC3 |
| 3282 | NJEN | NEW JERSEY NONFERROUS TRADING INC | | | SCAC4 |
| 3283 | NJF | Netjets Middle East | Callsign: Sunjet, | SA | AVCODES |
| 3284 | NJFK | NASH, JOHN FREDERICK | | | SCAC4 |
| 3285 | NJFU | NJ FROMENT AND COMPANY LIMITED | | GB | BIC |
| 3286 | NJGP | NANJING PETROLEUM TRANSPORTATION CO | | | SCAC4 |
| 3287 | NJIB | NATIONWIDE JUST IN TIME FREIGHT BRO | | | SCAC4 |
| 3288 | NJII | Norfolk and Western Ry. Co. | added 5/1983 | | NAKINA |
| 3289 | NJII | New Jersey, Indiana & Illinois R.R. Co. | 1/1975-1/1980; eliminated 5/1983 | | NAKINA |
| 3290 | NJII | New Jersey, Indiana & Illinois R.R. Co. | 1/75-1/80; eliminated 5/83 | | NRHS |
| 3291 | NJII | Norfolk and Western Ry. Co. | added 5/83 | | NRHS |
| 3292 | NJII | NORFOLK SOUTHERN [NORFOLK & WESTERN; NEW JERSEY, INDIANA & ILLINOIS RR.] | | | PWRC |
| 3293 | NJII | New Jersey, Indiana and Illinois Railroad (Norfolk and Western Railway) | | | RSRV |
| 3294 | NJIM | NEW JERSEY INTERNATIONAL MOVERS INC | | | SCAC3 |
| 3295 | NJJ | Nasjet Private Aviation Co., Ltd. | | SA | AVCODES |
| 3296 | NJJ | Nordjyske Jernbaner | | DK | VKM |
| 3297 | NJJQ | NEVE, JAMES J | | | SCAC3 |
| 3298 | NJKA | NEAL, J K AGENT | | | SCAC3 |
| 3299 | NJLC | NOBLE JUICES LLC | | | SCAC4 |
| 3300 | NJLI | NICHOLSON, J LAURANCE & SON INC | | | SCAC3 |
