| 1 | STH | South-Airlines LLC | | AM | AVCODES |
| 2 | STH | Southern Airlines Ltd. | | GB | AVCODES |
| 3 | STH | RTE / STH | Callsign: Zeltron, | F | AVCODES |
| 4 | STH | South-Airlines | | | ICAO1 |
| 5 | STH | Stern & Hafferl | | A | TRAFFIC |
| 6 | STH | Stern & Hafferl Verkehrsgesellschaft mbH | | AT | VKM |
| 7 | STHB | Süd-Thüringen-Bahn | Real: STB | D | TRAFFIC |
| 8 | STHC | SATHER TRUCKING COMPANY | | | SCAC4 |
| 9 | STHD | SCIEMA TECHNICAL SERVICES LTD | | | SCAC4 |
| 10 | STHEL | Stephenson's Helmsley | | GB | TRAFFIC |
| 11 | STHF | STASH FUEL OIL INC | | | SCAC4 |
| 12 | STHG | STRONGHURST GRAIN & | | | SCAC4 |
| 13 | STHI | STONE, H I & SON INC | | | SCAC4 |
| 14 | STHJ | ST NICHOLAS INC | | | SCAC4 |
| 15 | STHK | Straußberg-Herzfelder Kleinbahn | near Berlin | D | TRAFFIC |
| 16 | STHL | SOUTH-LAND FOODS INC | | | SCAC4 |
| 17 | STHM | STROEHER & SON TRANSPORT CO INC | | | SCAC4 |
| 18 | STHP | SOUTHWEST TRANSFER COMPANY | | | SCAC4 |
| 19 | STHR | SOUTHERN CORROSION CONTROL LTD | | | SCAC4 |
| 20 | STHS | STANDARD TRANSPORTATION SERVICES, INC | | | SCAC1 |
| 21 | STHS | STANDARD TRANSPORTATION SERVICES IN | | | SCAC4 |
| 22 | STHV | STARVIN MARVINS SEAFOODS | | | SCAC4 |
| 23 | STHX | Stauffer Chemical Co. of Nevada | 7/1954; eliminated 7/1956 | | NAKINA |
| 24 | STHX | Stauffer Chemical Co. of Nevada | eliminated 7/56 | | NRHS |
| 25 | STHX | STAUFFER CHEMICAL CO. OF NEVADA | | | PWRC |
