| 1 | HX | Trans North Aviation Ltd. | Designator HX* recalled by IATA | USA | AVCODES |
| 2 | HX | Hamburg Airlines, GmbH And Co. | ICAO: HAS, Callsign: Hamburg Air, Ceased operations | D | AVCODES |
| 3 | HX | Hainan Airlines Company Limited | ICAO: CHH, Callsign: Hainan, IATA designator changed from H4. IATA changed to HU | PRC | AVCODES |
| 4 | HX | South West Aviation Company Ltd. | Callsign: Swavia, | GB | AVCODES |
| 5 | HX | South West Aviation Company Ltd. | Callsign: Swavia, | GB | AVCODES |
| 6 | HX | Hong Kong Airlines Limited | ICAO: CRK, Callsign: Bauhinia, IATA Prefix: 851, IATA designator changed from N8* w.e.f. 27 May 2007. Name changed from CR Airways Limited. Designator N8* reinstated by IATA | HK | AVCODES |
| 7 | HX | Hickok Oil Corp. | 7/1932-1/1946 | | NAKINA |
| 8 | HX | Hickok Oil Corp. (General American Tank Car Corp.) | 7/1930 | | NAKINA |
| 9 | HX | Hickok Oil Corp. | Apr-38 | | NRHS |
| 10 | HX | HICKOK OIL CORP. 9GENERAL AMERICAN TANK CAR CO.) | | | PWRC |
| 11 | HX | Heathrow Express | 1999: standard gauge, electrified at 25kV 50Hz. The Heathrow Express service between London Paddington station and Heathrow Airport is operated by BAA plc, the airport authority. From June 1997 trains are operated between Paddington and the entrance of the tunnel under the airport, every 15 minutes. | GB | TRAFFIC |
| 12 | HX | Heathrow Express | | UK | VKM |
| 13 | HXA | China Express Airlines Co., Ltd | IATA: G5, Callsign: China Express, IATA Prefix: 987, | PRC | AVCODES |
| 14 | HXA | China Express Airlines | | | ICAO1 |
| 15 | HXA | Hamburg Airlines | Real: HX | D | TRAFFIC |
| 16 | HXAL | HELENS TRANSPORTATION LLC | | | SCAC4 |
| 17 | HXCC | HORNS EXPRESS | | | SCAC4 |
| 18 | HXCU | TIANJIN HUAXI TRADE & TRANSPORTATIO | | | SCAC4 |
| 19 | HXIC | HIGHLANDER XPRES INC | | | SCAC4 |
| 20 | HXKU | HEFEI XINKE ELECTRONIC MATERIAL CO., LTD | | PRC | BIC |
| 21 | HXL | ATR Leasing VI B.V. (Holland Exel) | IATA: YZ, Callsign: Holland Exel, Designator YZ reinstated by IATA | NL | AVCODES |
| 22 | HXLH | HERSON XPRESS LLC | | | SCAC4 |
| 23 | HXLI | HOUTEX LOGISTICS INC | | | SCAC4 |
| 24 | HXLL | HX LOGISTICS LLC | | | SCAC4 |
| 25 | HXLP | HOLLINGSWORTH EXPEDITING LANE PARTN | | | SCAC4 |
| 26 | HXNT | HEXION TRANSPORTATION INC | | | SCAC4 |
| 27 | HXPE | HARLAN XPRESS | | | SCAC4 |
| 28 | HXSI | HAMNER TRANSPORTATION SYSTEMS INC | | | SCAC4 |
| 29 | HXTL | HOOSON, ADAM TRANSPORT LTD | | | SCAC4 |
| 30 | HXTW | H TWO (H2) EXPRESS | | | SCAC4 |
