| 1 | UPA | Air Foyle Limited | IATA: GS, Callsign: Foyle, Designator recalled by IATA | GB | AVCODES |
| 2 | UPA | Air Foyle Limited | IATA: UP, Callsign: Foyle, IATA designator changed to GS | GB | AVCODES |
| 3 | UPA | Air Foyle Limited | Callsign: Foyle, Ceased operations. Designator recalled by IATA | GB | AVCODES |
| 4 | UPA | Air Foyle | IATA: GS | | ICAO1 |
| 5 | UPAC | UNITED PARCEL SERVICE COMPANY INC ( | | | SCAC4 |
| 6 | UPAO | UPDEGRAFF, MARK E | | | SCAC4 |
| 7 | UPAT | UPAT | | | SCAC4 |
| 8 | UPAU | CMC MATERIALS UPC LTD | | GB | BIC |
| 9 | UPAX | Utah Poultry Producers Cooperative Association Refrigerator Line | 7/1932 | | NAKINA |
| 10 | UPAX | Utah Poultry Producers Cooperative Association Refrigerator Line (North American Car Corp.) | 7/1935 | | NAKINA |
| 11 | UPAX | United Power Association | added 4/1982; 1/1994; eliminated 4/2000 | | NAKINA |
| 12 | UPAX | Great River Energy | added 4/2000; 7/2000-7/2005; eliminated 10/2005 | | NAKINA |
| 13 | UPAX | United Power Association | added 4/82; 1/94; eliminated 4/2000 | | NRHS |
| 14 | UPAX | Great River Energy | added 4/2000; 7/2000 | | NRHS |
| 15 | UPAX | *UTAH POULTRY PRODUCERS COOPERATIVE ASSOCIATION REFRIGERATOR LINE | | | PWRC |
| 16 | UPAX | *GREAT RIVER ENERGY [UNITED POWER ASSOCIATION] | | | PWRC |
| 17 | UPAX | United Power Association | | | RSRV |
