| 6001 | NTEU | SINTECO SRL | | I | BIC |
| 6002 | NTEW | NORSCHIF TRANSPORTES E SERVIEOS MAR | | | SCAC4 |
| 6003 | NTF | Piper OK | Callsign: Netflight, Name changed to OK Business Aircraft | CZ | AVCODES |
| 6004 | NTF | OK Business Aircraft | Callsign: Netflight, Name changed from Piper OK | CZ | AVCODES |
| 6005 | NTFF | NATIONWIDE TRAFFIC SERVICE | | | SCAC3 |
| 6006 | NTFI | NATIONAL FREIGHT INC | | | SCAC3 |
| 6007 | NTFI | NORDAN TANKERS 4 INC | | | SCAC4 |
| 6008 | NTFK | NOTT, FRANK H INC | | | SCAC3 |
| 6009 | NTFM | NATIONAL TRAFFIC SYSTEMS | | | SCAC4 |
| 6010 | NTFO | NOTTINGHAM TRANSFER CO | | | SCAC3 |
| 6011 | NTFQ | NATIONAL TRANSFER & STORAGE | | | SCAC3 |
| 6012 | NTFS | NU-TRANZ FREIGHT SYSTEMS INC | | | SCAC3 |
| 6013 | NTFT | NORTH TEXAS FUEL TRANSPORTATION 1 L | | | SCAC4 |
| 6014 | NTG | Servicios Integrales de Aviacion, S.A. de C.V. t/a FlyMex | Callsign: Integrales, | MEX | AVCODES |
| 6015 | NTG | Servicios Intergrales De Aviacion | | | ICAO1 |
| 6016 | NTG | NTG-BAU GmbH | | DE | VKM |
| 6017 | NTGE | NEUROSTREAM TECHNOLOGIES GP | | | SCAC4 |
| 6018 | NTGO | NOLAN TRANSPORTATION GROUP INC | | | SCAC4 |
| 6019 | NTGQ | NTG II | | | SCAC4 |
| 6020 | NTGR | NOVEO TECHNOLOGIES GROUP INC | | | SCAC4 |
| 6021 | NTGS | NATIONWIDE TRUCKING SERVICE INC | | | SCAC3 |
| 6022 | NTH | Hokkaido Air System Co. Ltd. | Callsign: North Air, | J | AVCODES |
| 6023 | NTH | Hokkaido Air System | | | ICAO1 |
| 6024 | NTHC | NORTHERN COACH INC | | | SCAC3 |
| 6025 | NTHC | NORTH COAST TRUCKING LTD | | | SCAC4 |
| 6026 | NTHE | NORTHERN EXPRESS INC | | | SCAC3 |
| 6027 | NTHI | NIGHT HAWK TRUCK LINES INC | | | SCAC4 |
| 6028 | NTHL | NORTHLAND TRANSPORTATION INC | | | SCAC3 |
| 6029 | NTHM | NATIONS TOWING & HEAVY EQUIPMENT HA | | | SCAC4 |
| 6030 | NTHN | NATHAN, RALPH CARTAGE | | | SCAC3 |
| 6031 | NTHP | NIGHTHAWK EXPRESS INC | | | SCAC4 |
| 6032 | NTHR | NORTHERN | | | SCAC3 |
| 6033 | NTHS | NAPOLEON TREES HAULINGS & SALES INC | | | SCAC4 |
| 6034 | NTHT | NITE-HAWK TRANSPORTATION | | | SCAC3 |
| 6035 | NTHT | NINE ONE ONE THREE-FIVE NINE SEVEN | | | SCAC4 |
| 6036 | NTHW | NORTHWESTERN TRUCKING INC | | | SCAC3 |
| 6037 | NTI | Aerocontinente Chile, S.A. | IATA: C7, Callsign: Continente, Designator C7* recalled by IATA. Designator C7* reinstated by IATA | RCH | AVCODES |
| 6038 | NTIA | NEEDHAM TRUCKING INC | | | SCAC4 |
| 6039 | NTIB | NORLING TRUCKING INC | | | SCAC4 |
| 6040 | NTIC | NITE INC | | | SCAC3 |
| 6041 | NTID | NUNEZ TRANSPORTATION INC | | | SCAC4 |
| 6042 | NTIE | N T I EXPRESS | | | SCAC3 |
| 6043 | NTIE | NINE ZERO TWO NINE-FOUR TWO FIVE SE | | | SCAC4 |
| 6044 | NTIF | NAT TRANS INC | | | SCAC4 |
| 6045 | NTIG | NEXUS TRADING INC | | | SCAC4 |
| 6046 | NTIH | NICKS TRUCKING INC | | | SCAC4 |
| 6047 | NTII | NTI INC | | | SCAC3 |
| 6048 | NTII | NORTH TEXAS INTERMODAL INC | | | SCAC4 |
| 6049 | NTIK | NORAS TRANSPORT INC | | | SCAC4 |
| 6050 | NTIM | N-TIME | | | SCAC3 |
| 6051 | NTIN | NORTHERN TOURS INC | | | SCAC3 |
| 6052 | NTIO | NATIONAL CAR RENTAL | | | SCAC3 |
| 6053 | NTIS | NORRIS TRANSPORTATION SERVICE | | | SCAC3 |
| 6054 | NTIU | GERMANISCHER LLOYD | | | PWRC |
| 6055 | NTIU | Germanischer Lloyd | | | RSRV |
| 6056 | NTIW | NOMAN TRANSPORTATION INC | | | SCAC4 |
| 6057 | NTIX | Network Trading Inc. | added 1/2004; eliminated 7/2004; added 1/2005; 7/2005; eliminated 7/2006 | | NAKINA |
| 6058 | NTIX | NETWORK TRADING, INC. | | | PWRC |
| 6059 | NTIX | NETWORK TRADING INC | | | SCAC4 |
| 6060 | NTIY | NICHOLLES TRUCKING INC | | | SCAC4 |
| 6061 | NTJ | NEX Time Jet AB | IATA: 2N, Callsign: Nextjet, Name changed to NextJet AB | S | AVCODES |
| 6062 | NTJ | NextJet AB | IATA: 2N, Callsign: Nextjet, Suspended all operations and filed for bankruptcy on 16 May 2018. Name changed from NEX Time Jet AB | S | AVCODES |
| 6063 | NTJ | NextJet | | | ICAO1 |
| 6064 | NTK | National Air Traffic Controllers Association (NATCA) | Callsign: NATCA, | USA | AVCODES |
| 6065 | NTK | Ocean Wings Commuter Service | Callsign: Tuckernuck, | USA | AVCODES |
| 6066 | NTK | Natioanl Air Traffic Controllers Association | | | ICAO1 |
| 6067 | NTKE | NOTTKE TRUCKING | | | SCAC3 |
| 6068 | NTKG | NOLANS TRUCKING | | | SCAC3 |
| 6069 | NTKG | NORRIS TRUCKING INC | | | SCAC4 |
| 6070 | NTKI | NEUMANN TRUCKING INC | | | SCAC3 |
| 6071 | NTKI | NATIONAL TRUCKLOAD INC | | | SCAC4 |
| 6072 | NTKL | NORTHERN TRUCKING AND LOGISTICS COR | | | SCAC4 |
| 6073 | NTKN | NEXUS TRUCK LINES | | | SCAC4 |
| 6074 | NTKO | NIEMAN TRUCKING LLC | | | SCAC4 |
| 6075 | NTKQ | NABEL TRUCKING CO | | | SCAC3 |
| 6076 | NTKS | NATALIE TANKSHIPS CORPORATION | | | SCAC3 |
| 6077 | NTKS | NATALIE TANKSHIPS CORPORATION | | | SCAC4 |
| 6078 | NTKU | NIPPON TANSAN CO LTD | | | SCAC4 |
| 6079 | NTKX | VAE Nortrak North America, Inc. | added 1/1999; 7/2000; eliminated 7/2001; 7/2005 (not listed) | | NAKINA |
| 6080 | NTKX | VAE Nortrak North America, Inc. | added 1/99; 7/2000; eliminated 7/2001 | | NRHS |
| 6081 | NTKX | VAE NORTRAK NORTH AMERICA INC. | | | PWRC |
| 6082 | NTKX | VAE Nortrak North America | | | RSRV |
| 6083 | NTKX | VAE NORTRAK NORTH AMERICA INC | | | SCAC4 |
| 6084 | NTL | Air Anatolia (Anadolu Havacilik A.S.) | Callsign: Air Anatolia, Name changed from GTI Havayollari A.S. Airloines, Inc. Ceased operations during 2002. Designator TD* recalled by IATA | TR | AVCODES |
| 6085 | NTL | Northair Aviation Ltd. | IATA: NT, Callsign: Northair, Merged into Knight Air during 1990 | GB | AVCODES |
| 6086 | NTL | GTI Havayollari A.S. Airlines, Inc. | IATA: TD, Callsign: Air Anatolia, Name changed to Air Anatolia (Anadolu Havacilik A.S.) | TR | AVCODES |
| 6087 | NTL | Air Anatolia | | | ICAO1 |
| 6088 | NTLA | NORWALK TRUCK LINES INC OF DELA | | | PWRC |
| 6089 | NTLA | NORWALK TRUCK LINES INC | | | SCAC3 |
| 6090 | NTLA | NOBLE DISTRIBUTION EAST LLC | | | SCAC4 |
| 6091 | NTLC | NATONAL CARTAGE CO | | | SCAC3 |
| 6092 | NTLD | NORWALK TRUCK LINES INC OF DELA | | | PWRC |
| 6093 | NTLD | NOCS TRANSPORT LTD. | | | SCAC3 |
| 6094 | NTLD | NOCS TRANSPORT LTD | | | SCAC4 |
| 6095 | NTLE | NELSON TRUCK LINES | | | SCAC3 |
| 6096 | NTLF | NATIONAL FREIGHT LINES | | | SCAC3 |
| 6097 | NTLG | NOVO TRANSPORTATION LOGISTICS, Novo Enterprises, INC | | | SCAC3 |
| 6098 | NTLG | NTL NAIGAI TRANS LINE (USA) INC | | | SCAC4 |
| 6099 | NTLH | NADLER TRANSPORT LTD | | | SCAC4 |
| 6100 | NTLI | NICKLAS TRUCK LINE | | | SCAC3 |
