Originally Posted by Aventine

I arrived at GH Incheon at 6:30am before and not having booked the previous night. Front desk asked for me to pay for the previous night and I agreed because was dead tired. Only to fight it later with the EAM and he agreed that as a hub airport location that flexible check in times were not unreasonable for Globalist travelers. Excellent service!

Asking kindly and early would be recommended and probably always granted.