| 1 | HPA | Pearl Airways Compagne Haitienne | Callsign: Pearl Airways, Designator HP recalled by IATA | RH | AVCODES |
| 2 | HPA | Pearl Airways Compagne Haitienne | IATA: HP, Callsign: Pearl Airways, Designator HP recalled by IATA | RH | AVCODES |
| 3 | HPA | Pearl Airways | IATA: HP | | ICAO1 |
| 4 | HPAM | HPA MOTORSPORTS INC | | | SCAC4 |
| 5 | HPAO | HAHN, PAUL & CO | | | SCAC4 |
| 6 | HPAR | HASSON, PATRICK | | | SCAC4 |
| 7 | HPAT | HPA TRANSPORT LLC | | | SCAC4 |
| 8 | HPAU | HIDROJEN PEROKSIT AS | | TR | BIC |
| 9 | HPAU | HIDROJEN PEROKSIT | | | SCAC4 |
| 10 | HPAX | International Paper Co. | added 1/1992; 1/1994-7/2005 | | NAKINA |
| 11 | HPAX | Hammermill Paper Co. | added 1/1971; 1/1975-1/1980; eliminated 1/1992 | | NAKINA |
| 12 | HPAX | Mather Stock Car Co. | 1/1950-1/1952 | | NAKINA |
| 13 | HPAX | Hunter Packing Co. (Mather Stock Car Co.) | 1/1941-4/1947 | | NAKINA |
| 14 | HPAX | Hunter Packing Co. | 7/1932-4/1938 | | NAKINA |
| 15 | HPAX | Hunter Packing Co. (Mather Stock Car Co.) | Apr-38 | | NRHS |
| 16 | HPAX | Mather Stock Car Co. | Jan-52 | | NRHS |
| 17 | HPAX | Hammermill Paper Co. | added 1/71; 1/75-1/80; eliminated 1/92 | | NRHS |
| 18 | HPAX | International Paper Co. | added 1/92; 1/94-7/2000 | | NRHS |
| 19 | HPAX | *MATHER STOCK CAR CO. [HUNTER PACKING CO.] | | | PWRC |
| 20 | HPAX | +(IPCX) INTERNATIONAL PAPER COMPANY (HAMMERMILL) | | | PWRC |
| 21 | HPAX | Hammermill Paper (International Paper) | | | RSRV |
| 22 | HPAX | INTERNATIONAL PAPER COMPANY | | | SCAC4 |
