| 601 | PARF | PARRAS TRUCKING | | | SCAC4 |
| 602 | PARG | PARR, GEORGE TRUCKING SERVICE INC | | | SCAC3 |
| 603 | PARG | PARGA TRUCKING | | | SCAC4 |
| 604 | PARH | PARISH OIL CO INC | | | SCAC4 |
| 605 | PARI | PARADIS INC | | | SCAC4 |
| 606 | PARK | PARK TRUCKING COMPANY, THE | | | SCAC3 |
| 607 | PARLA | Tranvia de Parla | City: Parla | E | TRAFFIC |
| 608 | PARN | PACIFIC & ARCTIC RAILROAD & NAVIGATION CO. | | | PWRC |
| 609 | PARN | PARROTT TRANSPORT COMPANY INC, THE | | | SCAC4 |
| 610 | PARO | PARSON, JACK B COMPANIES | | | SCAC4 |
| 611 | PARP | PARAMETERS UNLIMITED | | | SCAC3 |
| 612 | PARP | PARKERS PROPANE | | | SCAC4 |
| 613 | PARQ | P & R TRANSFER INC | | | SCAC3 |
| 614 | PARR | PARKER, RICHARD, INC | | | SCAC3 |
| 615 | PARS | PACIFIC RELOCATING SERVICES INC | | | SCAC3 |
| 616 | PART | PARIS TRUCKING COMPANY INC | | | SCAC4 |
| 617 | PARTL | Партнер Лизинг АД | | BG | VKM |
| 618 | PARU | PARAGUAY LINIE SCHIFFAHRTGESELL | | | SCAC3 |
| 619 | PARV | PARKHURST, VIRGIL | | | SCAC3 |
| 620 | PARW | PEARCE WORLDWIDE LOGISITCS INC | | | SCAC4 |
| 621 | PARX | Pan American Ry. Co. | added 4/1975; 1/1980-7/2005 | | NAKINA |
| 622 | PARX | Union Tank Car Co. | 10/1957; added 1/1958; 4/1961-10/1966; eliminated 10/1968 | | NAKINA |
| 623 | PARX | Sinclair Refining Co. | 7/1937-7/1954; eliminated 1/1958 | | NAKINA |
| 624 | PARX | Producers & Refiners Corp. (Sinclair Refining Co.) | 7/1935 | | NAKINA |
| 625 | PARX | Producers & Refiners Corp. | 7/1923-7/1932 | | NAKINA |
| 626 | PARX | Pan-American Refining Co. | 8/1920 | | NAKINA |
| 627 | PARX | Producers & Refiners Corp. (Sinclair Refining Co.) | Apr-38 | | NRHS |
| 628 | PARX | Sinclair Refining Co. | 1/52; eliminated 1/58 | | NRHS |
| 629 | PARX | Union Tank Car Co. | 10/57; added 1/58; 4/61-10/66; eliminated 10/68 | | NRHS |
| 630 | PARX | Pan American Ry. Co. | added 4/75; 1/80-7/2000 | | NRHS |
| 631 | PARX | *SINCLAIR REFINING CO. [PRODUCERS & REFINERS CORP.; PAN-AMERICAN REFINING CO.] | | | PWRC |
| 632 | PARX | *BLUE MOUNTAIN RAILROAD, INC. [PALOUSE RIVER RAILROAD CO.] | | | PWRC |
| 633 | PARX | +PAN AMERICAN RAILWAY COMPANY (UNION TANK CAR CO.) | | | PWRC |
| 634 | PARX | Pan American Railway | | | RSRV |
| 635 | PARX | PAN AMERICAN RAILWAY COMPANY | | | SCAC4 |
| 636 | PARX | Pan American Railway Copany | | USA | TRAFFIC |
| 637 | PARY | Prairie Trunk Ry. | 1/1980; added 4/1980; eliminated 10/1987 | | NAKINA |
| 638 | PARY | Prairie Trunk Ry. | 1/80; added 4/80; eliminated 10/87 | | NRHS |
| 639 | PARY | RETIRED 01-19-90 DMC (0777) [PRAIRIE TRUNK RY.] | | | PWRC |
| 640 | PARY | Prairie Trunk Railway | | | RSRV |
| 641 | PARY | PARRY, C D CO INC | | | SCAC4 |
| 642 | PARZ | PARK INDUSTRIES | | | PWRC |
| 643 | PAS | P.T. Pelita Air Service | IATA: 6D, Callsign: Pelita, IATA Prefix: 019, IATA designator changed to 6D. Designator 6D* reinstated by IATA | RI | AVCODES |
| 644 | PAS | P.T. Pelita Air Service | IATA: 6D, Callsign: Pelita, IATA Prefix: 019, IATA designator changed from 6D*. Designator 6D* reinstated by IATA | RI | AVCODES |
| 645 | PAS | P.T. Pelita Air Service | IATA: IP, Callsign: Pelita, IATA Prefix: 019, Designator 6D recalled by IATA. IATA designator changed from 6D*. Designator 6D* reinstated by IATA | RI | AVCODES |
| 646 | PAS | Pelita Air Service | | | ICAO1 |
| 647 | PAS | Pan Am Southern | | | RSRV |
| 648 | PAS | PAN AM SOUTHERN LLC | | | SCAC4 |
| 649 | PASB | PUTMAN & SONS BUS SERVICE | | | SCAC3 |
| 650 | PASB | POLSTON, ALLEN S | | | SCAC4 |
| 651 | PASC | PORT AUTHORITY OF SHELBY COUNTY | | | PWRC |
| 652 | PASC | PASCHALL TRUCK LINES INC | | | SCAC3 |
| 653 | PASC | PASCHALL TRUCK LINES INC (KY-CORP) | | | SCAC4 |
| 654 | PASG | PALM SPRINGS MOVING & STORAGE | | | SCAC3 |
| 655 | PASI | PACIFIC AIR SHIPPERS ASSN INC | | | SCAC3 |
| 656 | PASI | PATRON SING, FAUSTO | | | SCAC4 |
| 657 | PASJ | PASHA TRUCKING LLC | | | SCAC4 |
| 658 | PASK | PASCAL ENTERPRISE | | | SCAC3 |
| 659 | PASK | PASK FARMS LTD | | | SCAC4 |
| 660 | PASL | PASILLAS GUEVARA, MARISELA | | | SCAC4 |
| 661 | PASM | PASCALE, M TRUCKING, INC | | | SCAC3 |
| 662 | PASM | PASMEL EXPRESS INC | | | SCAC4 |
| 663 | PASN | PARSONS COAL COMPANY, INC | | | SCAC3 |
| 664 | PASN | PARSONS COAL COMPANY, INC | | | SCAC4 |
| 665 | PASO | PASCO PIPELINE COMPANY | | | SCAC3 |
| 666 | PASOLINI | Pasolini VCB | | I | TRAFFIC |
| 667 | PASP | PASCUZZO, M SAND & STONE SUPPLY INC | | | SCAC3 |
| 668 | PASQ | PASQUALE TRUCKING COMPANY INC | | | SCAC3 |
| 669 | PASQ | PASQUALE TRUCKING COMPANY INC | | | SCAC4 |
| 670 | PASR | PATRIOT TRANSPORT SOLUTIONS INC | | | SCAC4 |
| 671 | PASS | PROVINCIAL-AMERICAN TRUCK TRANSPORT | | | SCAC3 |
| 672 | PASS | PaSS spol s.r.o | | SK | VKM |
| 673 | PASSAT | Passic-Athenia Bus Company | | US-NJ | TRAFFIC |
| 674 | PASSV | Passaic Valley | | US-NJ | TRAFFIC |
| 675 | PAST | PARSONS TRANS, INC | | | SCAC3 |
| 676 | PAST | PARSONS TRANS INC | | | SCAC4 |
| 677 | PASU | PACIFIC LINES | | VN | BIC |
| 678 | PASU | PITT & SCOTT LTD | | | SCAC3 |
| 679 | PASV | PARK SERVICE CO INC | | | SCAC3 |
| 680 | PASV | PACART | | | SCAC4 |
| 681 | PASW | PASZKOWSKI TRANSPORT INC | | | SCAC4 |
| 682 | PASX | Pacer International d/b/a Pace Stacktrain | added 4/2000; 7/2000 (not listed); 7/2005 | | NAKINA |
| 683 | PASX | American Oil Co. | added 4/1957; 10/1957-10/1966; eliminated 4/1968 | | NAKINA |
| 684 | PASX | Pan-Am Southern Corp. | 1/1950-7/1954; eliminated 4/1957 | | NAKINA |
| 685 | PASX | Pan-Am Southern Corp. | 1/52; eliminated 4/57 | | NRHS |
| 686 | PASX | American Oil Co. | added 4/57; 10/57-10/66; eliminated 4/68 | | NRHS |
| 687 | PASX | Pacer International d/b/a Pace Stacktrain | added 4/2000; 7/2000 | | NRHS |
| 688 | PASX | *AMERICAN OIL CO. [PAN-AM SOUTHERN CORP.] | | | PWRC |
| 689 | PASX | *PASSUMPSIC RAILROAD | | | PWRC |
| 690 | PASX | +PACER INTERNATIONAL d/b/a PACER STACKTRAIN | | | PWRC |
| 691 | PASX | Pacer Stacktrain | | | RSRV |
| 692 | PASX | PACER INTERNATIONAL INC | | | SCAC4 |
| 693 | PASY | PENNSYLVANIA SECURITY CORPORATION | | | SCAC3 |
| 694 | PASY | PASCON | | | SCAC4 |
| 695 | PAT | Department Of The Army, Priority Air Transport (Davison Aviation Command) | Callsign: Pat, | USA | AVCODES |
| 696 | PAT | Paramount Airways | IATA: QJ, Callsign: Paramount, Founded in October 1986. Ceased operations on 15 November 1989. | GB | AVCODES |
| 697 | PAT | Priority Air Transport | | | ICAO1 |
| 698 | PAT | PORT AUTHORITY TRANSIT OF ALLEGHENY COUNTY (PITTSBURGH, | | | PWRC |
| 699 | PAT | Port Authority Transit (Pittsburgh - Allegheny county) | City: Pittsburgh | USA | TRAFFIC |
| 700 | PAT | Zakłady Naprawcze Taboru Kolejowego “PATEREK” S.A. | | PL | VKM |
