As far as I kow they can only be checked in a Disney resort at the front desk, or in any Disney theme park at Guest Relations. The Disney Stores or CRO cannot check for you. This is frustrating - I just found a bunch of misc. park hoppers & 1-day passes in our security box & have no idea if they're used or not - so now I can't get advance tickets before the trip, since I don't know how many days I need!