| 1 | PTA | Ptarmigan Airways Ltd. | IATA: 5P, Callsign: Ptarmigan, Designator 5P recalled by IATA. Bought and merged in First Air during 1995. | CDN | AVCODES |
| 2 | PTA | Pontair Limited | Callsign: Pontair, | M | AVCODES |
| 3 | PTA | Ptarmigan Airways | | | ICAO1 |
| 4 | PTAA | PORT AUTHORITY OF ALLEGHENY COUNTY | | | SCAC3 |
| 5 | PTAC | PALACE TRANSFER & STORAGE | | | SCAC3 |
| 6 | PTAC | PTI | | | SCAC4 |
| 7 | PTAD | POINT TRANSPORTATION INC | | | SCAC3 |
| 8 | PTAE | PETROFF TRUCKING & EXCAVATING CO | | | SCAC3 |
| 9 | PTAE | PP TRUCKING INC | | | SCAC4 |
| 10 | PTAF | PAULS TRANSFER (DIVISION OF LOOMIS | | | SCAC3 |
| 11 | PTAG | PREMIER TRANSPORTATION INC | | | SCAC3 |
| 12 | PTAG | PREMIER TRANSPORTATION | | | SCAC4 |
| 13 | PTAH | POE TRANSPORT | | | SCAC3 |
| 14 | PTAI | PORT AREA SERVICES INC | | | SCAC3 |
| 15 | PTAJ | PRIDE TRANSPORTATION COMPANY | | | SCAC3 |
| 16 | PTAJ | PILGRIM TRANSPORT LLC | | | SCAC4 |
| 17 | PTAK | PARRA TRUCKING | | | SCAC3 |
| 18 | PTAK | PRATUM TRANSPORTATION LLC | | | SCAC4 |
| 19 | PTAL | PENN TANK LINES INC | | | SCAC4 |
| 20 | PTAM | PALMER TRANSPORTATION INC | | | SCAC3 |
| 21 | PTAN | PETE AND ANNIES TRUCKING INC | | | SCAC4 |
| 22 | PTAO | PARK TRANSPORTATION INC | | | SCAC3 |
| 23 | PTAP | PETERSEN TRANSPORTATION INC | | | SCAC3 |
| 24 | PTAP | PETERSEN TRANSPORTATION INC | | | SCAC4 |
| 25 | PTAQ | PORTLAND AUTO DELIVERY CO | | | SCAC3 |
| 26 | PTAQ | PATIENT NEWS PUBLISHING LTD | | | SCAC4 |
| 27 | PTAS | PRO TRANSPORTATION SERVICES INC | | | SCAC3 |
| 28 | PTAS | PACTRANS AIR & SEA INC | | | SCAC4 |
| 29 | PTAT | PRIORITY TRANSPORTATION INC | | | SCAC3 |
| 30 | PTAT | PRIORITY TRANSPORTATION INC | | | SCAC4 |
| 31 | PTAU | INDUSTRIAL TRADE ALLIANCE LLC | | RUS | BIC |
| 32 | PTAV | PORTANOVA INC | | | SCAC3 |
| 33 | PTAV | PTI | | | SCAC4 |
| 34 | PTAW | PRIDE TRANSPORT | | | SCAC3 |
| 35 | PTAY | PATHWAY TRANSPORT LLC | | | SCAC4 |
