| 1 | PTX | Aereo Postal de Mexico, S.A. de C.V. | Callsign: Postalmex, | MEX | AVCODES |
| 2 | PTX | Private X-press | Callsign: Privatex, | CH | AVCODES |
| 3 | PTX | General American Transportation Corp. | 1/1946-7/1954; eliminated 4/1957 | | NAKINA |
| 4 | PTX | Pennsylvania-Conley Tank Line, a Division of General American Transportation Corp. | 7/1937-1/1945 | | NAKINA |
| 5 | PTX | Pennsylvania Tank Line (Pennsylvania-Conley Tank Line, a Division of General American Transportation Corp.) | 4/1938 | | NAKINA |
| 6 | PTX | Pennsylvania Tank Line (Pennsylvania-Conley Tank Car Co.) | 7/1935 | | NAKINA |
| 7 | PTX | Pennsylvania Tank Line (Pennsylvania-Conley Tank Line) | 7/1932 | | NAKINA |
| 8 | PTX | The Pennsylvania Tank Car Co. (Pennsylvania Tank Line) | 8/1920-7/1923 | | NAKINA |
| 9 | PTX | Pennsylvania Tank Line (Pennsylvania-Conley Tank Line, a Division of General American Transportation Corp.) | Apr-38 | | NRHS |
| 10 | PTX | Pennsylvania-Conley Tank Line, a Division of General American Transportation Corp. | Apr-38 | | NRHS |
| 11 | PTX | General American Transportation Corp. | 1/52; eliminated 4/57 | | NRHS |
| 12 | PTX | GENERAL AMERICAN TRANSPORTATION CORP. [PENNSYLVANIA-CONLEY TANK LINE; PENNSYLVANIA TANK CAR CO.] | | | PWRC |
| 13 | PTXB | PROTEXA BURLINGTON INTERNATIONAL | | | SCAC3 |
| 14 | PTXB | PINNACLE TRANSPORTATION LLC | | | SCAC4 |
| 15 | PTXD | PHILTEX LTD | | | SCAC4 |
| 16 | PTXE | PRESTON TRANSPORT INC | | | SCAC4 |
| 17 | PTXF | PEACE TRANSPORT LLC | | | SCAC4 |
| 18 | PTXG | PITA EXPRESS | | | SCAC4 |
| 19 | PTXH | POLER TRANSPORT INC | | | SCAC4 |
| 20 | PTXI | PTX INC | | | SCAC3 |
| 21 | PTXI | PACIFIC TRANS XPRESS INC | | | SCAC4 |
| 22 | PTXJ | PENINSULA TRANSPORTATION SERVICES | | | SCAC4 |
| 23 | PTXK | PEARL TRANSPORT LLC | | | SCAC4 |
| 24 | PTXL | PERFORMANCE TANK LINES INC | | | SCAC3 |
| 25 | PTXL | PETES EXPRESS LLC | | | SCAC4 |
| 26 | PTXM | PITTS TRANSPORTATION INC | | | SCAC4 |
| 27 | PTXN | PROA TRANSFER | | | SCAC4 |
| 28 | PTXP | PTX SERVICES LLC | | | SCAC4 |
| 29 | PTXQ | P & T TRANSPORT | | | SCAC4 |
| 30 | PTXR | PRIME TIME EXPRESS INC | | | SCAC3 |
| 31 | PTXS | PETROLEUM EXPRESS INC | | | SCAC3 |
| 32 | PTXS | PTR EXPRESS S DE RL DE | | | SCAC4 |
| 33 | PTXT | PATRIOT TRANSIT LLC | | | SCAC4 |
| 34 | PTXV | PERSONAL TOUCH TAXI SERVICES, A | | | SCAC3 |
| 35 | PTXW | POLAR TRANSPORT LLC | | | SCAC4 |
| 36 | PTXX | PTS Inc. | added 1/1993; 1/1994; eliminated 1/1999; 7/2000-7/2005 (not listed) | | NAKINA |
| 37 | PTXX | PTS Inc. | added 1/93; 1/94; eliminated 1/99; 7/2000 | | NRHS |
| 38 | PTXX | PTS, INCORPORATED | | | PWRC |
| 39 | PTXX | PTS Inc. | | | RSRV |
| 40 | PTXX | PTS, INCORPORATED | | | SCAC4 |
| 41 | PTXY | PS TRANSPORT INC | | | SCAC4 |
