| 1 | 6A | AVIACSA-Consorcio Aviaxsa, S.A. de C.V. | ICAO: CHP, Callsign: Aviacsa, IATA Prefix: 095, Founded in 1990. Ceased operations on 04 May 2011. | MEX | AVCODES |
| 2 | 6A | Armenia Airways Air company CJSC | ICAO: AMW, | AM | AVCODES |
| 3 | 6B | Britannia Airways AB | ICAO: BLX, Callsign: Bluescan, IATA Prefix: 951, Name changed to TUIFly Nordic AB w.e.f. 01 May 2006. Designator 6B* Reinstated by IATA | S | AVCODES |
| 4 | 6B | Blue Scandinavia | ICAO: BLX, Callsign: Bluescan, IATA Prefix: 951, Name changed to Britannia Airways AB w.e.f. 24 March 1998 | S | AVCODES |
| 5 | 6B | Baxter Aviation | | CDN | AVCODES |
| 6 | 6B | TUIfly Nordic AB | ICAO: BLX, Callsign: Bluescan, IATA Prefix: 951, Name changed from Britannia Airways AB w.e.f. 01 May 2006. Designator 6B* Reinstated by IATA | S | AVCODES |
| 7 | 6C | Cape Smythe Air | ICAO: CMY, Callsign: Cape Smythe Air, Designator 6C recalled by IATA | USA | AVCODES |
| 8 | 6C | Carib Aviation Limited | ICAO: DEL, Callsign: Red Tail, IATA designator changed to 3Q | AG | AVCODES |
| 9 | 6C | Centrafrrique Air Express (C.A.E.) | | RCA | AVCODES |
| 10 | 6C | Austasia Airlines S.A. | IATA Prefix: 586, Name changed to Air Timor S.A. | TL | AVCODES |
| 11 | 6C | Air Timor S.A. | IATA Prefix: 586, Name changed from Austasia Airlines S.A. | TL | AVCODES |
| 12 | 6C | Connect Linhas Aereas S.A. | ICAO: CNT, Callsign: Connect Cargo, IATA Prefix: 677, AOC voluntarily revoked on 16 March 2020. | BR | AVCODES |
| 13 | 6D | P.T. Pelita Air Service | ICAO: PAS, Callsign: Pelita, IATA Prefix: 019, IATA designator changed to 6D. Designator 6D* reinstated by IATA | RI | AVCODES |
| 14 | 6D | P.T. Pelita Air Service | ICAO: PAS, Callsign: Pelita, IATA Prefix: 019, IATA designator changed from 6D*. Designator 6D* reinstated by IATA | RI | AVCODES |
| 15 | 6D | Air Dominicana S.A. | ICAO: RDO, Callsign: Air Dom, | DOM | AVCODES |
| 16 | 6D | Royal Daisy Airlines | ICAO: KDR, Callsign: Darlines, | EAU | AVCODES |
| 17 | 6D | Travel Service,a.s. organizacna zlozka Slovensko (Organizational unit Slovakia) | ICAO: TVQ, Callsign: Slovaktravel, Name changed to Travel Service Slovensko s.r.o. | SK | AVCODES |
| 18 | 6D | Travel Service Slovensko s.r.o. | ICAO: TVQ, Callsign: Slovaktravel, Name changed to Smartwings Slovensko s.r.o. w.e.f. 10 December 2018. Name changed from Travel Service,a.s. organizacna zlozka Slovensko (Organizational unit Slovakia) | SK | AVCODES |
| 19 | 6D | Smartwings Slovensko s.r.o. | ICAO: TVQ, Callsign: Slovaktravel, Name changed from Travel Service Slovensko s.r.o. w.e.f. 10 December 2018. Name changed from Travel Service,a.s. organizacna zlozka Slovensko (Organizational unit Slovakia) | SK | AVCODES |
| 20 | 6E | Burrard Air (1989) Ltd. | ICAO: BXA, Callsign: Burrard, | CDN | AVCODES |
| 21 | 6E | Malmo Aviation AB | ICAO: SCW, Callsign: Scanwings, Designator 6E recalled by IATA | S | AVCODES |
| 22 | 6E | City Air Germany AG | ICAO: CIP, Callsign: Cityways, Ceased operations on 27 February 2004. | D | AVCODES |
| 23 | 6E | Interglobe Aviation Ltd. d/b/a Indigo | ICAO: IGO, Callsign: Ifly, IATA Prefix: 312, | IND | AVCODES |
| 24 | 6F | Afrijet Airlines | ICAO: FRJ, Callsign: Afrijet, Ceased operations in 2009. | WAN | AVCODES |
| 25 | 6F | Aerotrans Airlines Ltd. | ICAO: PFO, Callsign: Cyprus Aerotrans, IATA Prefix: 299, Desigantor 6F reinstated by IATA | CY | AVCODES |
| 26 | 6F | Laker Airways, Inc. | ICAO: LKR, Callsign: Laker, Ceased operations | USA | AVCODES |
| 27 | 6F | Falcon Air Express, Inc. | ICAO: FAO, Callsign: Panther, Commenced operations in May 1996. Suspended all operation and returned AOC on 05 June 2015. | USA | AVCODES |
| 28 | 6F | MAT Airways Ltd. | | MK | AVCODES |
| 29 | 6F | Primera Air Nordic | ICAO: PRW, Callsign: Jetbird, Ceased operations on 01 October 2018. | LV | AVCODES |
| 30 | 6G | Air Wales Limited | ICAO: AWW, Callsign: Red Dragon, Ceased schedule operations April 2006. ICAO callsign changed from Air Cymru | GB | AVCODES |
| 31 | 6G | Las Vegas Airlines | | USA | AVCODES |
| 32 | 6G | Gulfstream Air Charter, Inc. | ICAO: FDY, Callsign: Friendly, Name changed to Sun Air Express, LLC. | USA | AVCODES |
| 33 | 6G | Gabon Airlines Cargo | ICAO: GBK, | G | AVCODES |
| 34 | 6G | Go2Sky spol s.r.o. | ICAO: RLX, Callsign: Relaxair, | SK | AVCODES |
| 35 | 6G | Sun Air Express, LLC | ICAO: FDY, Callsign: Friendly, Merged into Southern Airways Express on 07 March 2016. Name changed from Gulfstream Air Charter, Inc. | USA | AVCODES |
| 36 | 6H | Israir Airlines and Tourism Ltd. | ICAO: ISR, Callsign: Israir, | IL | AVCODES |
| 37 | 6I | Aviast Ltd, Joint-Stock Company | ICAO: VVA, Callsign: Ialsi, IATA Prefix: 335, Designator 6I* recalled by IATA | RUS | AVCODES |
| 38 | 6I | IBA International Business Airlines AB | ICAO: IBZ, Callsign: Interbiz, Ceased operations. | S | AVCODES |
| 39 | 6I | Alsie Express | ICAO: MMD, Callsign: Mermaid, Operated by Air Alsie | DK | AVCODES |
| 40 | 6J | Southeast European Airlines | ICAO: GRE, Callsign: Seea Air, Ceased operations | GR | AVCODES |
| 41 | 6J | Skyservice Airlines, Inc. | ICAO: SSV, Callsign: Skytour, IATA Prefix: 884, IATA Designator changed to 5G. Name changed from Skyservice Airlines Inc. d/b/a Skyservice Roots Air | CDN | AVCODES |
| 42 | 6J | Skyservice Airlines, Inc. | ICAO: SSV, Callsign: Skytour, IATA Prefix: 884, Name changed to Skyservice Airlines Inc. d/b/a Skyservice Roots Air | CDN | AVCODES |
| 43 | 6J | Skyservice Airlines Inc. d/b/a Skyservice Roots Air | ICAO: SSV, Callsign: Skytour, IATA Prefix: 884, Name reverts to Skyservice Airlines Inc. on 04 May 2001. Name changed from Skyservice Airlines Inc. | CDN | AVCODES |
| 44 | 6J | Skynet Asia Airways | ICAO: SNJ, Callsign: Newsky, Designator 6J recalled by IATA | J | AVCODES |
| 45 | 6J | Jubba Airways (K) Limited | ICAO: JBW, Callsign: Airjub, | EAK | AVCODES |
| 46 | 6J | Skynet Asia Airways t/a Solaseed Air | ICAO: SNJ, Callsign: Newsky, Name changed from Skynet Asia Airways. IATA designator changed from LQ*. Designator 0E recalled by IATA | J | AVCODES |
| 47 | 6J | Solaseed Air Inc. | ICAO: SNJ, Callsign: Newsky, Name changed from Skynet Asia Airways. IATA designator changed from LQ*. Designator 0E recalled by IATA | J | AVCODES |
| 48 | 6K | Asian Spirit, Inc. | ICAO: RIT, Callsign: Asian Spirit, Established in 1995. Commenced operations in April 1996. Name changed to Zest Airways w.e.f. 30 September 2008. Designator 6K reinstated by IATA | RP | AVCODES |
| 49 | 6K | Keewatin Air Ltd. | ICAO: KEW, Callsign: Blizzard, IATA designator changed to FK*. Founded in 1998. in 1998. | CDN | AVCODES |
| 50 | 6K | Inter Express Hava Tasimacilik A.S. | ICAO: INX, Callsign: Inter-Euro, Founded on 17 December 1999. Ceased operations on 18 November 2008. | TR | AVCODES |
| 51 | 6K | Kyrgyz Trans Avia Ltd. Airline | ICAO: KTC, Ceased operations. | KS | AVCODES |
| 52 | 6K | Sky King, Inc. | ICAO: SGB, Callsign: Songbird, Operations resumed on 22 December 2014. Founded in July 1990. Ceased operation on 26 January 2014. Designator F3* recalled by IATA | USA | AVCODES |
| 53 | 6K | Songbird Airways, Inc. | ICAO: SGB, Callsign: Songbird, Name changed from Sky King, Inc in June 2015. | USA | AVCODES |
| 54 | 6L | Aklak Air, Inc. | ICAO: AKK, Callsign: Aklak, IATA Prefix: 709, Designator 6L recalled by IATA. | CDN | AVCODES |
| 55 | 6L | Aircompany Sun Light | ICAO: SUH, Callsign: Light Air, | KS | AVCODES |
| 56 | 6L | CargoLogic Germany GmbH | ICAO: GCL, Callsign: Saxonian, IATA Prefix: 342, | D | AVCODES |
| 57 | 6M | Majestic Air P/L | ICAO: MJC, Callsign: Zimbird, IATA Prefix: 066, Designator 6M recalled by IATA | ZW | AVCODES |
| 58 | 6M | Euroair Ltd. | ICAO: EUP, Callsign: Eurostar, Designator 6M* recalled by IATA | GR | AVCODES |
| 59 | 6M | 40 Mile Air | ICAO: MLA, Callsign: Mile Air, IATA designator changed to Q5* | USA | AVCODES |
| 60 | 6M | South Asia Airways | Designator 6M recalled by IATA | BD | AVCODES |
| 61 | 6M | Maverick Airways Corporation | ICAO: MVR, Callsign: Mav-Air, Designator 6M* recalled by IATA | USA | AVCODES |
| 62 | 6M | Air Minas Linhas Aereas Ltda | ICAO: AMG, Callsign: Air Minas, Founded in 2002. Ceased operations on 30 May 2010. Operating licence revoked on 20 September 2011. | BR | AVCODES |
| 63 | 6M | Linkair Express S.p.A. | ICAO: LKX, Callsign: Muttley, Commenced operations in April 2006. | I | AVCODES |
| 64 | 6M | Maximus Airlines | ICAO: MXM, Callsign: Maxlines, IATA Prefix: 387, | UA | AVCODES |
| 65 | 6M | Zacarías Moreno SL (Frigocontainer) | Non-airline Unit Load Devices (ULD) companies | E | AVCODES |
| 66 | 6N | Aerosucre, S.A. | ICAO: KRE, Callsign: Aerosucre, Designator 6N recalled by IATA. Founded in 1969. | CO | AVCODES |
| 67 | 6N | Trans Travel Airlines (TTA) | ICAO: TRQ, Callsign: Hunter, Ceased operations on 07 January 2003. Desginator 6N* reinstated by IATA. Formerly known as Turdus Airways B.V. | NL | AVCODES |
| 68 | 6N | Nunasi-Central Airlines Ltd. | ICAO: NUN, Callsign: Nunsai, Designator 6N recalled by IATA | CDN | AVCODES |
| 69 | 6N | Nordic NR Regional AB | ICAO: NRD, Callsign: Northrider, Name changed to Nordic Airways AB | S | AVCODES |
| 70 | 6N | Nordic Airways AB | ICAO: NRD, Callsign: Northrider, Sweden's Transport Authority has revoked the Air Operators licence. Name changed from Nordic NR Regional AB | S | AVCODES |
| 71 | 6N | Al-Naser Airlines | ICAO: MHK, Callsign: Al-Naser, IATA Prefix: 503, Designator 6N recalled by IATA | IRQ | AVCODES |
| 72 | 6N | Niger Airlines S.A. | ICAO: NIN, Callsign: Niger Airlines, | RN | AVCODES |
| 73 | 6O | Air Satellite, Inc. | ICAO: ASJ, Callsign: Satellite, Sold to Exactair Feb 2008. Designator HV recalled by IATA | CDN | AVCODES |
| 74 | 6O | Orbest Airlines, S.L. | ICAO: OBS, Callsign: Orbest, Name changed to Orbest Airlines, S.L. d/b/a iberojet. IATA desigantor changed from 4O. Subsidary of Iberworld, Spain. | P | AVCODES |
| 75 | 6O | Orbest Airlines, S.L. d/b/a iberojet | ICAO: OBS, Callsign: Orbest, Name changed from Orbest Airlines, S.L. IATA desigantor changed from 4O | P | AVCODES |
| 76 | 6P | DAC Air, S.A. | ICAO: GCP, Ceased operations | RO | AVCODES |
| 77 | 6P | Air Tracia | | RO | AVCODES |
| 78 | 6P | Sixcargo S.p.A. | ICAO: ISG, Callsign: Italcargo, Name changed to Clubair Sixgo S.p.A. | I | AVCODES |
| 79 | 6P | Propair, Inc. | ICAO: PRO, Callsign: Propair, Designator recalled by IATA | CDN | AVCODES |
| 80 | 6P | Peace Air (Private) Limited | ICAO: PCA, Callsign: Peace Air, | CL | AVCODES |
| 81 | 6P | Pacific East Air, Inc. | ICAO: PCE, | USA | AVCODES |
| 82 | 6P | Clubair Sixgo S.p.A. | ICAO: ISG, Callsign: Italcargo, Name changed from Sixcargo S.p.A. | I | AVCODES |
| 83 | 6P | Rovos Air (Pty) Ltd t/a Gryphon Airline | ICAO: VOS, Callsign: Rovos, | ZA | AVCODES |
| 84 | 6P | Pradhaan Air Express Private Ltd | ICAO: PRX, Callsign: Pradhaan, IATA Prefix: 339, JV between Astral Aviation (Kenya) and UAE-based lessor Vaayu Group. Planned start up with A320-200(P2F). | IND | AVCODES |
| 85 | 6Q | Slovak Airlines, Inc. | ICAO: SLL, Callsign: Slov Line, IATA Prefix: 921, IATA designator changed from 9S | SK | AVCODES |
| 86 | 6Q | Sham Wings Airlines | ICAO: SAW, Callsign: Shamwings, IATA Prefix: 386, Name changed to Cham Wings Airlines | SYR | AVCODES |
| 87 | 6Q | Cham Wings Airlines | ICAO: SAW, Callsign: Shamwings, IATA Prefix: 386, Designator 6Q reinstated by IATA. Name changed from Sham Wings Airlines | SYR | AVCODES |
| 88 | 6Q | AAR Airlift Group, Inc. | | USA | AVCODES |
| 89 | 6Q | Cham Wings Airlines | ICAO: SAW, Callsign: Shamwings, IATA Prefix: 386, Designator 6Q reinstated by IATA. Name changed from Sham Wings Airlines | SYR | AVCODES |
| 90 | 6R | Georgian Airlines | ICAO: GEG, IATA Prefix: 684, Designator 6R recalled by IATA | GE | AVCODES |
| 91 | 6R | Aerotransporte de Carga Union, S.A. de C.V. | ICAO: TNO, Callsign: Aerounion, IATA Prefix: 873, Founded on 05 March 1998. | MEX | AVCODES |
| 92 | 6R | BritRail Ltd. | ICAO: n/a, Designator 6R* recalled by IATA. Railway Service | GB | AVCODES |
| 93 | 6R | Alrosa Company Limited Mirny Air | ICAO: DRU, Designator 6R reinstated by IATA | RUS | AVCODES |
| 94 | 6R | Open Joint Stock Company "ALROSA" (Mirny Air Enterprise) | ICAO: DRU, Callsign: Mirny, Designator 6R reinstated by IATA | RUS | AVCODES |
| 95 | 6R | Air Affaires Afrique | Founded in 1978. Ceased operations during 2003. | CAM | AVCODES |
| 96 | 6S | Sahara Airlines | ICAO: SHD, Founded in 1998 and started operations in September 1999. Ceased operations. Designator 6S* recalled by IATA | DZ | AVCODES |
| 97 | 6S | Kato Airline AS | ICAO: KAT, Callsign: Kato-Air, Designator 6S recalled by IATA | N | AVCODES |
| 98 | 6S | El Sol de America, C.A. | ICAO: ESC, Callsign: Solamerica, | YV | AVCODES |
| 99 | 6S | Star Air Aviation (Private) Limited | ICAO: URJ, Callsign: Starav, | PK | AVCODES |
| 100 | 6S | SaudiGulf Airlines | ICAO: SGQ, Callsign: Saudi Gold, Designator 6S recalled by IATA.Commence domestic operations on 29 October 2016. Wholly owned by Abdul Hadi Al Qahtani Group of Companies. | SA | AVCODES |
