Originally Posted by CPH-Flyer

I never tried if I can get a boarding pass from OLCI in London. But if you can, no reason why you would not be able to use it more than 3 hours before.

Your passport will need to be checked, but if nothing else they will do it at the gate.

Originally Posted by JL41

JAL desks open 3 hours before departure of JL42 (in the morning) and then again for JL44 (in the afternoon). Last time I flew the route was 18 April and I could not get a boarding pass from online check-in. However, vaccination/PCR was still required at that time- Not sure if things have changed.