| 1 | NIH | Nippon Airship Corporation | | J | AVCODES |
| 2 | NIHH | NICHOLS HEAVY HAULING | | | SCAC3 |
| 3 | NIHL | NICHOLS, A T TRUCKING CO INC | | | SCAC3 |
| 4 | NIHON | Nihon Kotsu Co. | | J | TRAFFIC |
| 5 | NIHW | NITEHAWK EXPRESS INC | | | SCAC3 |
| 6 | NIHX | General Electric Rail Services Corp. | added 1/2000; 7/2000-7/2005 | | NAKINA |
| 7 | NIHX | General Electric Railcar Services Corp. | added 1/1984; 1/1994; eliminated 1/2000 | | NAKINA |
| 8 | NIHX | North American Car Corp. | added 4/1960; 4/1961-1/1980; eliminated 1/1984 | | NAKINA |
| 9 | NIHX | North American Car Corp. | 4/61-1/80 | | NRHS |
| 10 | NIHX | General Electric Railcar Services Corp. | 1/94; eliminated 1/2000 | | NRHS |
| 11 | NIHX | General Electric Rail Services Corp. | added 1/2000; 7/2000 | | NRHS |
| 12 | NIHX | (NATX) GENERAL ELECTRIC RAIL SERVICES CORP. [NORTH AMERICAN CAR CORP.] | | | PWRC |
| 13 | NIHX | GE Rail Services | | | RSRV |
| 14 | NIHX | GENERAL ELECTRIC RAILCAR SERVICES C | | | SCAC4 |