| 1 | PT | West Air Sweden AB | ICAO: SWN, Callsign: Air Sweden, IATA Prefix: 869, Designator PT reinstated by IATA | S | AVCODES |
| 2 | PT | Capital Cargo International Airlines, Inc. | ICAO: CCI, Callsign: Cappy, IATA Prefix: 721, Merged into Air Transport International in 2013. | USA | AVCODES |
| 3 | PT | Provincetown-Boston Airlines, Inc. | Callsign: Provincetown, | USA | AVCODES |
| 4 | PT | Piedmont Airlines, Inc. | ICAO: PDT, Callsign: Piedmont, IATA designator changed from US* | USA | AVCODES |
| 5 | PT | Peninsula Terminal Co. | 1/1975; added 7/1978; 1/1980; added 10/1986; 1/1994-7/2005 | | NAKINA |
| 6 | PT | Peoria Terminal Co. (Chicago, Rock Island & Pacific Ry.) | 7/1935-4/1938 | | NAKINA |
| 7 | PT | Peoria Terminal Co. | 7/1932 | | NAKINA |
| 8 | PT | Peoria Terminal Co. (Chicago, Rock Island & Pacific Ry.) | Apr-38 | | NRHS |
| 9 | PT | Peninsula Terminal Co. | 1/75; added 7/78; 1/80; added 10/86; 1/94-7/2000 | | NRHS |
| 10 | PT | *PEORIA TERMINAL CO. (CHICAGO, ROCK ISLAND & PACIFIC RWY.) | | | PWRC |
| 11 | PT | +PENINSULA TERMINAL COMPANY | | | PWRC |
| 12 | PT | Peninsula Terminal | | | RSRV |
| 13 | PT | PROGRESS TRADING, a.s. | | SK | VKM |
| 14 | PTA | Ptarmigan Airways Ltd. | IATA: 5P, Callsign: Ptarmigan, Designator 5P recalled by IATA. Bought and merged in First Air during 1995. | CDN | AVCODES |
| 15 | PTA | Pontair Limited | Callsign: Pontair, | M | AVCODES |
| 16 | PTA | Ptarmigan Airways | | | ICAO1 |
| 17 | PTAA | PORT AUTHORITY OF ALLEGHENY COUNTY | | | SCAC3 |
| 18 | PTAC | PALACE TRANSFER & STORAGE | | | SCAC3 |
| 19 | PTAC | PTI | | | SCAC4 |
| 20 | PTAD | POINT TRANSPORTATION INC | | | SCAC3 |
| 21 | PTAE | PETROFF TRUCKING & EXCAVATING CO | | | SCAC3 |
| 22 | PTAE | PP TRUCKING INC | | | SCAC4 |
| 23 | PTAF | PAULS TRANSFER (DIVISION OF LOOMIS | | | SCAC3 |
| 24 | PTAG | PREMIER TRANSPORTATION INC | | | SCAC3 |
| 25 | PTAG | PREMIER TRANSPORTATION | | | SCAC4 |
| 26 | PTAH | POE TRANSPORT | | | SCAC3 |
| 27 | PTAI | PORT AREA SERVICES INC | | | SCAC3 |
| 28 | PTAJ | PRIDE TRANSPORTATION COMPANY | | | SCAC3 |
| 29 | PTAJ | PILGRIM TRANSPORT LLC | | | SCAC4 |
| 30 | PTAK | PARRA TRUCKING | | | SCAC3 |
| 31 | PTAK | PRATUM TRANSPORTATION LLC | | | SCAC4 |
| 32 | PTAL | PENN TANK LINES INC | | | SCAC4 |
| 33 | PTAM | PALMER TRANSPORTATION INC | | | SCAC3 |
| 34 | PTAN | PETE AND ANNIES TRUCKING INC | | | SCAC4 |
| 35 | PTAO | PARK TRANSPORTATION INC | | | SCAC3 |
| 36 | PTAP | PETERSEN TRANSPORTATION INC | | | SCAC3 |
| 37 | PTAP | PETERSEN TRANSPORTATION INC | | | SCAC4 |
| 38 | PTAQ | PORTLAND AUTO DELIVERY CO | | | SCAC3 |
| 39 | PTAQ | PATIENT NEWS PUBLISHING LTD | | | SCAC4 |
| 40 | PTAS | PRO TRANSPORTATION SERVICES INC | | | SCAC3 |
| 41 | PTAS | PACTRANS AIR & SEA INC | | | SCAC4 |
| 42 | PTAT | PRIORITY TRANSPORTATION INC | | | SCAC3 |
| 43 | PTAT | PRIORITY TRANSPORTATION INC | | | SCAC4 |
| 44 | PTAU | INDUSTRIAL TRADE ALLIANCE LLC | | RUS | BIC |
| 45 | PTAV | PORTANOVA INC | | | SCAC3 |
| 46 | PTAV | PTI | | | SCAC4 |
| 47 | PTAW | PRIDE TRANSPORT | | | SCAC3 |
| 48 | PTAY | PATHWAY TRANSPORT LLC | | | SCAC4 |
| 49 | PTB | Passaredo Transportes Aereos, S.A. | IATA: Y8, Callsign: Passaredo, IATA Prefix: 837, Ceased operations on 18 April 2002. | BR | AVCODES |
| 50 | PTB | Passaredo Transportes Aereos, S.A. | IATA: P3, Callsign: Passaredo, IATA designator changed to 2Z | BR | AVCODES |
| 51 | PTB | Passaredo Transportes Aereos, S.A. t/a VOEPASS | IATA: 2Z, Callsign: Passaredo, IATA designator changed to 2Z | BR | AVCODES |
| 52 | PTB | Passaredo Transportes Aereos | | | ICAO1 |
| 53 | PTBC | PETERSBURG OIL COMPANY | | | SCAC4 |
| 54 | PTBE | POWER TRANSPORTATION INC | | | SCAC4 |
| 55 | PTBF | PITE, BRIAN FREIGHT INC | | | SCAC4 |
| 56 | PTBH | PATENAUDE-TREMP | | | SCAC4 |
| 57 | PTBI | PRIME TRANSPORT INC | | | SCAC3 |
| 58 | PTBI | PRIME TRANSPORT INC | | | SCAC4 |
| 59 | PTBJ | PAOLI TRANSPORT | | | SCAC4 |
| 60 | PTBL | PREMIER TANK LINES | | | SCAC3 |
| 61 | PTBM | P.A.T. TRANSPORT | | | SCAC3 |
| 62 | PTBP | PRESTIGE TRANSPORT INC | | | SCAC4 |
| 63 | PTBQ | PROFESSIONAL TRANSPORTATION BROKERS | | | SCAC4 |
| 64 | PTBR | PATTERSON BROS TRUCKING | | | SCAC3 |
| 65 | PTBR | PETROBRAS AMERICA INC | | | SCAC4 |
| 66 | PTBS | POST TIME BUS SERVICE | | | SCAC3 |
| 67 | PTBU | GCATAINER BV | | NL | BIC |
| 68 | PTBU | GCATAINER BV | | | SCAC4 |
| 69 | PTBV | PERFORMANCE TRANSPORTATION CORP | | | SCAC4 |
| 70 | PTBW | PREMIER TRANSPORTATION | | | SCAC4 |
| 71 | PTBY | PIONNA TRANSPORT LLC | | | SCAC4 |
| 72 | PTC | Patria Cargas Aereas, S.A. | Callsign: Patria, | USA | AVCODES |
| 73 | PTC | Pilot Training College | Callsign: Mentor, | IRL | AVCODES |
| 74 | PTC | Patria Cargas Aereas | | | ICAO1 |
| 75 | PTC | Plainview Terminal Co. | added 1/1996; eliminated 4/1997; 7/2000-7/2005 | | NAKINA |
| 76 | PTC | Peoria Terminal Co. | 1/1975-1/1980 | | NAKINA |
| 77 | PTC | Peoria Terminal Co. | 1/75-1/80 | | NRHS |
| 78 | PTC | Plainview Terminal Co. | added 1/96; eliminated 4/97; 7/2000 | | NRHS |
| 79 | PTC | PLAINVIEW TERMINAL COMPANY (CODE FORMERLY USED BY PEORIA TERMINAL) | | | PWRC |
| 80 | PTC | Plainview Terminal | | | RSRV |
| 81 | PTC | PLAINVIEW TERMINAL COMPANY | | | SCAC4 |
| 82 | PTC | Philadelphia Transportation Co. | | USA | TRAFFIC |
| 83 | PTCA | PATTEE, CLARE INC | | | SCAC3 |
| 84 | PTCA | PTC AIR FREIGHT INC | | | SCAC4 |
| 85 | PTCB | PURPOSE TRANSPORTATION CORP | | | SCAC4 |
| 86 | PTCC | PITTMAN CONSTRUCTION COMPANY | | | SCAC4 |
| 87 | PTCE | PETRO CARRIERS INC | | | SCAC4 |
| 88 | PTCG | PETERSON CARTAGE CO | | | SCAC3 |
| 89 | PTCI | PINE TIMBER CO INC | | | SCAC3 |
| 90 | PTCJ | PRIORITY ONE TRANSPORT CORP | | | SCAC3 |
| 91 | PTCJ | PRITCHARD, CAROL J | | | SCAC4 |
| 92 | PTCL | PORT CITY LEASING | | | SCAC3 |
| 93 | PTCM | PRO-TECH ELECTRONIC MOVERS | | | SCAC3 |
| 94 | PTCM | PRINTERY COMMUNICATIONS INC | | | SCAC4 |
| 95 | PTCN | PRODUCT TRANSPORT CORPORATION | | | SCAC3 |
| 96 | PTCO | PURE TRANSPORTATION COMPANY | | | SCAC3 |
| 97 | PTCP | POLANC TRUCKING INC | | | SCAC4 |
| 98 | PTCQ | PERIMETER TRANSPORTATION CO INC | | | SCAC4 |
| 99 | PTCS | PETROLEUM CARRIERS INC | | | SCAC4 |
| 100 | PTCT | PARTCO TRUCKING CO INC | | | SCAC3 |
