I have about 6 months left on my passport, and I'm thinking of renewing it right now while I'm back home.
I still have a couple of reservations with United--one of which is still in progress--which I made with my current (soon to be expired) passport number. If I renew my passport right now, will I have any problems when I try to check-in for my upcoming flight? Do I have to call United or something to get my passport number on file changed?