Originally Posted by
FlyerJ
The agent at the call centre couldn’t answer your question?
If he/she didn’t know - and since you’ve exhausted every “non airport” option - that would probably indicate that there’s no way of doing it in advance ... and you’ll need to see an agent at check-in at the airport to correct it.
I’m not sure why, but it seems that all airlines (that I’ve used, at least) lock both passport info and KTN numbers once they’re entered on a reservation — they can’t be edited afterwards.
When the Passport and KTN information is entered it is transmitted along with other APIS information to the relevant foreign authorities. It is typically requested as soon after booking that the information becomes available, so that they can run their intelligence analytics on it. From a booking system perspective, it is generally a design principle that APIS information for a record is only transmitted once. I'm not sure what flags or checks incorrectly entered information cause at immigration.