| 1 | PI | Sun Air (Pacific) Limited. | ICAO: SUF, Callsign: Sunflower, IATA Prefix: 252, Designator PI recalled by IATA. Name changed from Sunflower Airlines Ltd. IATA designator changed from 2S | FJI | AVCODES |
| 2 | PI | Sunflower Airlines Ltd. | ICAO: SUF, Callsign: Sunflower, IATA Prefix: 252, Name changed to Sun Air (Pacific) Limited. IATA designator changed from 2S | FJI | AVCODES |
| 3 | PI | Piedmont Airlines, Inc. | ICAO: PAI, Callsign: Piedmont, Merged into UsAir | USA | AVCODES |
| 4 | PI | Syrian Pearl Airlines | ICAO: PSB, | SYR | AVCODES |
| 5 | PI | Aviation Matters, Inc. (PacificFlyer) | ICAO: PFL, IATA Prefix: 213, Designator PI* recalled by IATA. | PAL | AVCODES |
| 6 | PI | Sol del Paraguay Lineas Aereas S.A. | ICAO: SGU, Callsign: Solparaguayo, Founded on 15 May 2010. Commenced operations on 15 June 2011. Ceased operations on 01 August 2012. | PY | AVCODES |
| 7 | PI | Polar Airlines OJSC | ICAO: RKA, Callsign: Air Sakha, Name changed from Polar Airlines, , State Unitary Enterprise Air Company. Purchased by JSC Airline Yakutia (R3/SYL) | RUS | AVCODES |
| 8 | PI | Paducah & Illinois R.R. | 1/1975-7/2005 | | NAKINA |
| 9 | PI | Paducah & Illinois R.R. | 1/75-7/2000 | | NRHS |
| 10 | PI | PADUCAH & ILLINOIS RAILROAD | | | PWRC |
| 11 | PI | Paducah and Illinois Railroad | | | RSRV |
| 12 | PIA | Pakistan International Airlines | IATA: PK, Callsign: Pakistan, IATA Prefix: 214, | PK | AVCODES |
| 13 | PIA | Pakistan International Airlines | IATA: PK | | ICAO1 |
| 14 | PIA | Pakistan International Airlines | | PK | TRAFFIC |
| 15 | PIAC | PIT STOP FUELS | | | SCAC4 |
| 16 | PIAD | PIERCE, ALDEN | | | SCAC3 |
| 17 | PIAD | PICARD, A D METAL USA INC | | | SCAC4 |
| 18 | PIAF | PIONEER SHIP SUPPLY INC | | | SCAC4 |
| 19 | PIAH | PINEAPPLE HOLDINGS INC | | | SCAC3 |
| 20 | PIAJ | PINOLI, ARTHUR JOHN | | | SCAC3 |
| 21 | PIAN | PIERCY, PAUL W TRUCKING | | | SCAC3 |
| 22 | PIAO | PIASA OILS TRANSPORT INC | | | SCAC3 |
| 23 | PIAO | PIASA OILS TRANSPORT LLC | | | SCAC4 |
| 24 | PIAP | PITTMAN LOGISTICS AND TRANSPORTATIO | | | SCAC4 |
| 25 | PIAS | PINELAND FARMS LTD | | | SCAC4 |
| 26 | PIAT | PICK-A-TREAT INC | | | SCAC3 |
| 27 | PIAU | TRANSPORTS PIALLA | | | SCAC4 |
| 28 | PIBA | PIONEER NAVIGATION LTD | | | SCAC4 |
| 29 | PIBC | PACGRAN INC | | | SCAC4 |
| 30 | PIBD | PINE BELT DISTRIBUTORS INC | | | SCAC3 |
| 31 | PIBL | PINE BLUFF WAREHOUSE CO | | | SCAC3 |
| 32 | PIBL | PINE BLUFF TRUCK DRIVING SCHOOL INC | | | SCAC4 |
| 33 | PIBM | PIBOMULTI | | | SCAC4 |
| 34 | PIBO | PIEDMONT DISTRIBUTION CENTER | | | SCAC3 |
| 35 | PIBT | PITRE BROS TRANSFER, INC | | | SCAC3 |
| 36 | PIBT | PHILS TRANSPORT INC | | | SCAC4 |
| 37 | PIC | Pacific Airlines Co. Ltd. | IATA: BL, Callsign: Pacific Express, IATA Prefix: 550, Name changed to Jetstar Pacific w.e.f. 23 May 2008. | VN | AVCODES |
| 38 | PIC | Jetstar Pacific Airlines Co. Ltd. | IATA: BL, Callsign: Pacific Express, IATA Prefix: 550, Name changed to Pacific Airlines Co. Ltd. Name changed from Pacific Airlines Co. Ltd. w.e.f. 23 May 2008. | VN | AVCODES |
| 39 | PIC | Pacific Airlines Co. Ltd. | IATA: BL, Callsign: Pacific Express, IATA Prefix: 550, Name changed from Jetstar Pacific Airlines Co. Ltd. and previously from Pacific Airlines Co. Ltd. w.e.f. 23 May 2008. | VN | AVCODES |
| 40 | PIC | Pacific Airlines | IATA: BL | | ICAO1 |
| 41 | PICB | PICORP TRANSPORT INC | | | SCAC3 |
| 42 | PICB | PICORP INC BALTIMORE | | | SCAC4 |
| 43 | PICC | PICON TRANSPORTATION INC | | | SCAC3 |
| 44 | PICC | PROLOGIC INC | | | SCAC4 |
| 45 | PICE | PICKENS ENTERPRISES INC | | | SCAC3 |
| 46 | PICE | PICKENS ENTERPRISES INC | | | SCAC4 |
| 47 | PICF | PITTS CARTAGE INC | | | SCAC3 |
| 48 | PICF | P I XPRESS INC | | | SCAC4 |
| 49 | PICG | PICKERING, ORAL G | | | SCAC3 |
| 50 | PICH | PICHE, ALAIN TRANSPORT INC | | | SCAC4 |
| 51 | PICH | Pichenot Bouillé | | F | TRAFFIC |
| 52 | PICI | PANICI TRUCKING | | | SCAC3 |
| 53 | PICI | PENTAGON LOGISTICS INC | | | SCAC4 |
| 54 | PICJ | PHAETHON INTERNATIONAL COMPANY SA | | | SCAC4 |
| 55 | PICJ | Jetstar Pacific | | VDR | TRAFFIC |
| 56 | PICK | The Pickens R.R. Co. | added 7/1973; 1/1975-1/1980; eliminated 10/1992; eliminated 10/1993; 1/1994 (not listed); eliminated 1/1995; 7/2000-7/2005 | | NAKINA |
| 57 | PICK | The Pickens R.R. Co. | added 7/73; 1/75-1/80; eliminated 10/92; eliminated 10/93; 1/94; eliminated 1/95; 7/2000 | | NRHS |
| 58 | PICK | PICKENS RAILWAY CO. | | | PWRC |
| 59 | PICK | Pickens Railroad | | | RSRV |
| 60 | PICK | PICKENS RAILROAD COMPANY | | | SCAC3 |
| 61 | PICK | PICKENS RAILWAY COMPANY | | | SCAC4 |
| 62 | PICK | Pickens Railway | | USA | TRAFFIC |
| 63 | PICL | PIONEER CARLOADING COMPANY (DIV OF | | | SCAC3 |
| 64 | PICL | PIONEER CARLOADING COMPANY (DIV OF | | | SCAC4 |
| 65 | PICM | PICKELNER, MORRIS | | | SCAC3 |
| 66 | PICM | PREMIER FREIGHT INC | | | SCAC4 |
| 67 | PICN | PICKETT TRUCKING | | | SCAC3 |
| 68 | PICO | PIERCE & SON TRUCKING | | | SCAC3 |
| 69 | PICO | PRAIRIE INTERNATIONAL CONTAINER & D | | | SCAC4 |
| 70 | PICP | PRINCETON INDUSTRIES CORP, P I C | | | SCAC3 |
| 71 | PICP | PLANES MOVING & STORAGE COMPANY OF | | | SCAC4 |
| 72 | PICQ | PICKENS-KANE MOVING & STORAGE CO | | | SCAC3 |
| 73 | PICS | PIC | | | SCAC4 |
| 74 | PICT | PICO TRANSPORTATION CO INC | | | SCAC3 |
| 75 | PICU | AUTOTRASPORTI PICCININI S.R.L. | | I | BIC |
| 76 | PICU | PICKFORDS REMOVALS LTD | | | PWRC |
| 77 | PICU | Pickfords Removals Limited | | | RSRV |
| 78 | PICU | PICKFORDS REMOVALS LTD | | | SCAC3 |
| 79 | PICU | AUTOTRASPORTI PICCININI S A S | | | SCAC4 |
| 80 | PICW | PIC-WALSH FREIGHT CO | | | PWRC |
| 81 | PICW | PLASMA INNOVATION COOKWARE INC | | | SCAC4 |
| 82 | PICX | Pioneer Ice Cream Division, The Borden Corp. | 1/1950 | | NAKINA |
| 83 | PICX | The Penn Iron & Coal Co. | 8/1920-7/1923 | | NAKINA |
| 84 | PICX | *PENN IRON & COAL CO. | | | PWRC |
| 85 | PICX | *PIONEER ICE CREAM DIV., THE BORDON CORP. | | | PWRC |
| 86 | PICX | TRINITY MANUFACTURING INC | | | SCAC4 |
| 87 | PICY | PERRY ICE CREAM COMPANY INC | | | SCAC3 |
| 88 | PICZ | PLYMOUTH INDUSTRY COMPLEX | | | PWRC |
| 89 | PIDB | PIERSON DISTRIBUTING | | | SCAC3 |
| 90 | PIDB | PILLETTE TRANSFER STATION LTD | | | SCAC4 |
| 91 | PIDE | PRIDE ENTERPRISES | | | SCAC3 |
| 92 | PIDI | PIONEER DELIVERY SERVICE | | | SCAC3 |
| 93 | PIDI | PHOENIX INTERACTIVE DESIGN INC | | | SCAC4 |
| 94 | PIDL | PIER DELIVERIES INC | | | SCAC3 |
| 95 | PIDL | PIONEER TRANSPORTATION LLC | | | SCAC4 |
| 96 | PIDM | PLATT & SON INC | | | SCAC4 |
| 97 | PIDN | PACIFIC ISLE DELIVERY INC | | | SCAC3 |
| 98 | PIDN | PIRTLE, DANNY NURSERY INC | | | SCAC4 |
| 99 | PIDO | PULIDO'S TOWING | | | SCAC4 |
| 100 | PIDS | PIONEER DRIVER SERVICES INC | | | SCAC3 |
