| 1 | IPP | Unifly Srl | IATA: IP, Callsign: India Papa, Name changed from Unifly | I | AVCODES |
| 2 | IPPC | IDAHO POTATO PACKERS CORPORATION OF | | | SCAC4 |
| 3 | IPPI | IMPACT POWER PRODUCTS INC | | | SCAC4 |
| 4 | IPPP | INTERNATIONAL POWER PRESS CORP | | | SCAC4 |
| 5 | IPPX | Intermountain Power Agency | added 1/1985; eliminated 4/1985; added 1/1986; 1/1994; eliminated 7/1999; 7/2000-7/2005 (not listed) | | NAKINA |
| 6 | IPPX | Iowa Poultry Products Association (North Western Refrigerator Line Co.) | 7/1935 | | NAKINA |
| 7 | IPPX | Iowa Poultry Products Association | 7/1932 | | NAKINA |
| 8 | IPPX | Intermountain Power Agency | added 1/85; eliminated 4/85; added 1/86; 1/94; eliminated 7/99; 7/2000 | | NRHS |
| 9 | IPPX | *IOWA POULTRY PRODUCTS ASSOCIATION | | | PWRC |
| 10 | IPPX | +INTERMOUNTAIN POWER AGENCY | | | PWRC |
| 11 | IPPX | Intermountain Power Agency | | | RSRV |
| 12 | IPPX | INTERMOUNTAIN POWER PROJECT | | | SCAC4 |
