| 1 | NLA | Peninsula Airways, Inc. t/a PenAir | IATA: KS, Callsign: Peninsula, IATA Prefix: 339, IATA designator KS recalled by IATA. | USA | AVCODES |
| 2 | NLA | Neiltown Air Ltd. | Callsign: Neiltown Air, | CDN | AVCODES |
| 3 | NLA | Peninsula Airways, Inc. t/a PenAir | Callsign: Peninsula, IATA designator KS recalled by IATA. | USA | AVCODES |
| 4 | NLA | Neiltown Air | | | ICAO1 |
| 5 | NLAD | NIGRO, LOUIS ALEXANDER | | | SCAC4 |
| 6 | NLAE | NO LIMITS TRUCKING | | | SCAC4 |
| 7 | NLAF | NLNOVALINK | | | SCAC4 |
| 8 | NLAN | N-LAND TRANSPORTATION INC | | | SCAC3 |
| 9 | NLAN | NOLANS FARM EQUIPMENT INC | | | SCAC4 |
| 10 | NLAS | NELSON A V & SONS | | | SCAC3 |
| 11 | NLAT | NEAL, AUSTIN TRUCKING | | | SCAC3 |
| 12 | NLAT | NYK LOGISTICS AMERICAS-TRANSPORTATI | | | SCAC4 |
| 13 | NLAU | NRS LOGISTICS AMERICA INC. | | USA | BIC |
| 14 | NLAX | National Aeronautics and Space Administration | added 4/1966; 10/1966-4/1970; eliminated 10/1974; added 7/1982; 1/1994-7/2000; eliminated 1/2004; 7/2005 (not listed) | | NAKINA |
| 15 | NLAX | National Aeronautics and Space Administration | added 4/66; 10/66-4/70; eliminated 10/74; added 7/82; 1/94-7/2000 | | NRHS |
| 16 | NLAX | NATIONAL AERONAUTICS & SPACE ADM. (NASA) | | | PWRC |
| 17 | NLAX | National Aeronautics and Space Administration (NASA) | | | RSRV |
| 18 | NLAX | NATIONAL AERONAUTICS & SPACE | | | SCAC4 |
