| 1 | HRS | Hellas Air Service, S.A. | Callsign: Hellas Air, | GR | AVCODES |
| 2 | HRS | Pursuit Aviation | Callsign: Horseman, | USA | AVCODES |
| 3 | HRS | Holidaysburg and Roaring Spring R.R. Co. | 7/2000-7/2005 | | NAKINA |
| 4 | HRS | Holidaysburg and Roaring Spring R.R. Co. | Jul-00 | | NRHS |
| 5 | HRS | Hoyer Railserv GmbH | Hamburg | D | privat-bahn.de |
| 6 | HRS | HOLIDAYSBURG & ROARING SPRING RAILROAD CO. | | | PWRC |
| 7 | HRS | Hollidaysburg and Roaring Spring Railroad | | | RSRV |
| 8 | HRS | HOLLIDAYSBURG AND ROARING SPRING RA | | | SCAC4 |
| 9 | HRSB | HARRISONBURG MOTOR EXPRESS | | | SCAC4 |
| 10 | HRSC | HIRSCHMAN OIL SUPPLY INC | | | SCAC4 |
| 11 | HRSD | HARRIS, R S TRANSPORT LTD | | | SCAC4 |
| 12 | HRSE | HARTSELL TRUCKING | | | SCAC1 |
| 13 | HRSH | HRS HOT RUNNER SYSTEMS NA INC | | | SCAC4 |
| 14 | HRSJ | HARBOR BUNKERING CORPORATION | | | SCAC4 |
| 15 | HRSL | HARVEY SALT COMPANY | | | SCAC4 |
| 16 | HRSO | HAUSER, R F SHOWS LTD | | | SCAC4 |
| 17 | HRSQ | HARRIS QUALITY INC | | | SCAC4 |
| 18 | HRSS | H R S TRANSPORT INC | | | SCAC4 |
| 19 | HRST | HURST TRUCKING | | | SCAC4 |
| 20 | HRSU | HUELIN RENOUF SHIPPING LIMITED | | | SCAC4 |
| 21 | HRSW | HERZOG, STEVEN W | | | SCAC4 |
| 22 | HRSX | Harbor Rail Services of California, Inc. | 7/2005 (not listed) | | NAKINA |
| 23 | HRSX | Heritage Ry. Service, Inc. | added 7/1986; eliminated 1/1990 | | NAKINA |
| 24 | HRSX | Heritage Ry. Service, Inc. | added 7/86; eliminated 1/90 | | NRHS |
| 25 | HRSX | *HAWAIIAN RAILWAY SOCIETY | | | PWRC |
| 26 | HRSX | +HARBOR RAIL SERVICES OF CALIFORNIA [HERITAGE RAILWAY SERVICE INC.] | | | PWRC |
| 27 | HRSX | Harbor Rail Services of California | | | RSRV |
| 28 | HRSX | HARBOR SERVICES OF CALIFORNIA INC | | | SCAC4 |
