Why does a flight show in one GDS but not another?

A flight shows in one GDS and not another because each airline decides, system by system, what it sells there. It chooses how closely it connects to each GDS, which fares it files where, which fares it keeps for NDC or its own website, and what extra it charges per booking. Private fares for your office, seat availability and the odd commercial dispute do the rest.

Who decides what a GDS shows?

The airline. A GDS (Amadeus, Sabre or Travelport) shows what each airline has agreed to distribute through it, on the terms of that airline's contract with that GDS. Three airlines can sit in the same GDS on three different deals.

Travelport's help pages describe three levels at which an airline or other vendor can take part: a direct real-time link, with instant availability and confirmation; regular updates without an instant link, where staff must message the vendor to confirm; and no direct link, where both availability and confirmation go by message (Travelport, "Vendor Participation Levels"). The other GDSs work with similar levels under their own names. So an airline can show live seats in one system and a delayed or partial picture in another.

Why are some fares only in NDC or on the airline's website?

Because airlines want you to book them there. NDC lets the airline build the offer itself, and some airlines keep part of their fares out of the classic (EDIFACT) GDS channel:

• American Airlines removed about 40% of its fares from EDIFACT channels on 3 April 2023 and made them NDC-only (Cranky Flier, 27 July 2023). In June 2024 it began returning fare content to the GDSs, but basic economy stays NDC-only (Business Travel Executive, 13 June 2024).
• United took Basic Economy fares (US domestic and short-haul Latin America) out of EDIFACT channels from 5 September 2023 (Cranky Flier).
• Turkish Airlines keeps "NDC-only promotional fares" and its rich content for agencies connected to TKCONNECT, its NDC platform (Business Travel Executive, 16 May 2024).
• Lufthansa Group gives a "Base Offer" through NDC in the GDSs and a "Smart Offer" through its direct ("bilateral") NDC model (Lufthansa Group DCC Guideline, valid from 1 January 2026). So two channels show two different sets of fares for the same flight.

Whether you see NDC fares in your GDS at all depends on your office. In Amadeus, for example, NDC is enabled per office. More in What is NDC? Explained for travel agencies.

Why is the same flight more expensive in one GDS?

Because several airlines add a charge to tickets issued through the classic GDS channel, and the amount differs by GDS:

Lufthansa Group also sets its charge by point of origin: a ticket starting in the US pays USD 21 through Amadeus, for example (LHG guideline). These charges change often, so check the airline's agency pages before you quote.

Why don't I see a private or corporate fare?

Because private fares are filed for specific agencies and markets. Travelport's checklist for missing fares names the usual causes: the agency's office (PCC) isn't added to the private fare's security; the fare's sales restrictions don't match where and how you sell; the currency or passenger type is wrong; or the account code isn't entered (Travelport, "Missing Fares"). The same logic applies in every GDS: a negotiated fare loaded for one agency's office won't show for another agency, even in the same system.

Why do seats and connections differ?

Two more reasons, both about how a GDS builds what you see:

• Seat availability. With a direct real-time link the GDS asks the airline live; without one it shows the airline's last update, which can be out of date (the participation levels above). A class shown open may then fail when you sell it.
• Connection building. Minimum connecting times are agreed data sets: the airport sets a default and airlines file their own exceptions. OAG handles over 157,000 of them, "used by global distribution systems (GDS) and connection builders" (OAG, 12 July 2023). Each GDS's low-fare search also caps how many options it returns: Amadeus's Flight Offers Search returns at most 250 (Amadeus API specification). So two systems can build and keep a different set of connections for the same trip.

Airlines also judge seats by the whole journey, not flight by flight, so a connection must be sold as one trip. Selling it one flight at a time can be refused, or fined later.

Why does an airline disappear from a GDS?

A commercial dispute between the airline and the GDS:

• Sabre removed all Turkish Airlines content on 1 September 2024. Turkish bookings could no longer be serviced in Sabre, so ticketing, reissues and cancellations went to the airline (Travel Market Report, 30 August 2024). Turkish content returned to Sabre under a new deal in June 2025 (Travel Bulletin).
• American Airlines sued Sabre in January 2011 over its display and booking fees. They settled on 30 October 2012 with a renewed multi-year distribution deal (AMR Corp Form 10-K, 2012).

What about low-cost carriers?

Each one decides for itself:

• easyJet renewed its distribution deals with Travelport, Amadeus and Sabre by February 2020 (Travolution, 13 February 2020).
• Ryanair ended its Amadeus partnership on 15 December 2017, keeping Travelport and Sabre (Travolution, 8 December 2017). In 2026 it set new booking terms for agencies that book it through Amadeus, Sabre or Travelport; through Amadeus it promises fare parity with its website and no surcharges (Travel Extra, 28 July 2026).
• Wizz Air took its first flight content aggregator, Travelfusion, live in all markets on 19 August 2025 (Travelfusion). We found no public source for Wizz Air in any GDS.

Who is where? Airlines by channel

What we could source on 17 October 2026. A dash means we found no public source, not that the answer is no.

Sources for each row are in the sections above and under Sources. The NDC dates: Lufthansa Group on Amadeus (Lufthansa Group, 13 September 2022) and Travelport+ (Travelport, 5 December 2023); Air France-KLM on Travelport+ (Travel Market Report, 13 January 2023) and Sabre (PATA, 7 May 2025); British Airways on Travelport+ (AJOT, 3 August 2023) and Sabre (Sabre, March 2025); Emirates on Sabre (Sabre, 3 December 2024); American in all three (American Airlines, 24 October 2022).

How do you check why a fare is missing?

Five questions, in this order:

1. Is the airline in your GDS, and live? Check its participation, or ask your GDS help desk.
2. Is the fare NDC-only? Compare with the airline's website, and ask your account manager whether NDC is enabled for your office for that airline.
3. Is it a private fare? Check that your office is authorised and the account code is in your entry.
4. Does the point of sale match? Some fares are only for sale in certain countries or currencies.
5. Is it a low-cost carrier? It may sell only direct, or through an aggregator or its approved partners.

Can one search cover two GDSs?

Yes. GateRoam connects Claude, ChatGPT or any MCP client to your agency's own Amadeus and Travelport+ (Galileo) contracts. With both connected, one search asks both: one list, each option marked Amadeus or Travelport, the same flights shown once at the lower price. The price check, the hold and the booking entries then go back to the system that found the option. Travelport+ (Galileo) MCP · Galileo MCP: connect Claude and ChatGPT to Travelport+.

How the providers themselves compare: Amadeus vs Sabre vs Travelport vs Duffel for travel agencies. And the four kinds of channel side by side: GDS vs NDC vs low-cost carriers vs aggregators. GateRoam is free during early access. Start free.

Sources

Checked on 17 October 2026.

• Travelport: Vendor Participation Levels
• Travelport: Missing Fares
• Lufthansa Group: DCC Guideline, valid from 1 January 2026
• Travel Market Report: Lufthansa Group charge from 5 May 2026, 6 April 2026
• Cranky Flier: American and United fares out of EDIFACT, 27 July 2023
• Business Travel Executive: American returning fares to the GDSs, 13 June 2024
• Business Travel Executive: Turkish Airlines TKCONNECT and GDS fee, 16 May 2024
• TourMaG: Air France-KLM GDS surcharge, 5 November 2024
• TTG Asia: British Airways and Iberia GDS fee, 31 May 2017
• Travolution: BA and Iberia charge increase, 7 September 2018
• Skift: British Airways' parent IAG and Amadeus, 26 February 2021
• Travel News: Emirates GDS surcharge, 2 March 2021
• Travolution: Emirates and Travelport, 2 July 2021
• GTP: Emirates and Amadeus, 27 January 2022
• OAG: Minimum connection times, 12 July 2023
• Amadeus: Flight Offers Search API specification
• Travel Market Report: Sabre drops Turkish Airlines, 30 August 2024
• Travel Bulletin: Turkish Airlines back on Sabre, June 2025
• AMR Corp Form 10-K: American Airlines and Sabre, 2011–2012
• Travolution: easyJet GDS deals, 13 February 2020
• Travolution: Ryanair and Amadeus, 8 December 2017
• Travel Extra: Ryanair GDS booking terms, 28 July 2026
• Travelfusion: Wizz Air and Travelfusion, 19 August 2025
• NDC go-live sources: Lufthansa Group, Travelport, Travel Market Report, PATA, AJOT, Sabre, Sabre, American Airlines