We have flight from Manchester to Heathrow then Heathrow to HK flying weeks time. I’m trying to input API but it just keeps saying it’s too early to check in (which I know and not trying to as that’s 24 hours prior to flight. Could it be you do this on check in…: I read on BA websight can be done prior ????



Thanks

I found this post on the BA forum on FlyerTalk which might be applicable for your situation. I'll paste the paragraph here as well as a link you may (or may not?) find relevant. I know it mentions OLCI in the title but it covers much more. And yes, you can provide it at check in on the day. Best wishes!

3) Have you submitted the right Advance Passenger (API) information? Is your ESTA / eTA up to date?
Particularly for travel to the USA and Canada, your passport number on the booking is checked against databases to check your ESTA or eTA status. The weblink above, under Traveller Information will show the passport on the booking. There's a separate bug in this area where the system seems to keep requested API despite it being done - one workaround is to edit the API, change a letter, reverse the change, save and then go straight to OLCI. Some other things to look for: have you changed your passport since the booking? Also some countries require passports to not expire within 6 months after the arrival date. Your BAEC account may populate your bookings with default data but it may not be correct for this particular booking. For example dual nationals with US passports must travel to the USA on US passports, and that must show in the API.

https://www.flyertalk.com/forum/british-airways-british-airways-club/1883989-faq-why-can-t-i-check-online-olci-boarding-pass-difficulties.html