| 1 | 5Q | Keenair Charter Ltd. | ICAO: JFK, Callsign: Keenair, | GB | AVCODES |
| 2 | 5Q | Euroceltic Airways Limited | ICAO: ECY, Callsign: Echelon, Ceased Operations on 21 January 2003. Designator 5Q reinstated by IATA. Name changed from Atlantic Bridge AviationLtd. d/b/a Sky Trek Airlines | GB | AVCODES |
| 3 | 5Q | Skargardsflyg AB | ICAO: LND, Callsign: Aaland, Designator 5Q recalled by IATA | FIN | AVCODES |
| 4 | 5Q | Atlantic Bridge AviationLtd. d/b/a Sky Trek Airlines | Name changed to Euroceltic Airways Limited | GB | AVCODES |
| 5 | 5Q | Best Aviation Ltd. | ICAO: BEA, Callsign: Best Air, Founded in 2007. Ceased operations in 2009. | BD | AVCODES |
| 6 | 5Q | Los Cipreses S.A. d/b/a BQB Lineas Aéreas | ICAO: BQB, IATA Prefix: 567, Suspened operations on 11 April 2015. Commenced operations in May 2010. Subsidiary of ferry company Buquebus. | ROU | AVCODES |
| 7 | 5Q | Holiday Europe Ltd. | ICAO: HES, Callsign: Holiday Europe, IATA Designator changed to 5Q. | BG | AVCODES |
| 8 | 5Q | Holiday Europe Ltd. | ICAO: HES, Callsign: Holiday Europe, IATA Prefix: 062, IATA Designator changed from 5Q*. | BG | AVCODES |
