Originally Posted by
Confus
There is a ‘hard limit’ of 364 days for any airline that uses a GDS to host their bookings, but airlines can choose any limit they like within that. For practical reasons it’s sensible to give a bit of a buffer, so BA’s 355 is about the most generous it could be (short of changing the GDS build, which immediately brings major complexity and £££££ which just isn’t worth it for what is and will remain a tiny number of people booking that far out).
Airlines that aren’t IATA members and don’t use GDSs can do what they like, which is why Thomson and similar will sell itineraries for the year after next.
A lot will be to do with the underlying GDS that powers each airlines reservation system. Amadeus is the system powering BA reservations and availability and Amadeus works as far out as 355 days. American on the other hand is powered by the Sabre GDS and works as far out as 330 days. Worth mentioning you can't get around the issue by booking with a 3rd party agent who uses an alternative GDS. In the case of AA, they just won't show up as bookable if checking on BA.com or with an agent using Amadeus. Similarly Sabre agents struggle to secure availability on heavy demand BA flights because their furthest booking window is 25 days shorter than that of BA's system (I'm looking at you here Amex!)