Redeem to travel Japan from 4,000 miles one-way or 8,000 miles round trip
Reservation changes are not permitted. (Boarding class cannot be changed either)*
You cannot change your flight at the airport on the day of departure, even if there are seats available on a different flight for the same segment.
However, you may upgrade your flight to Class J or First Class for a fee on the day of departure if there are available seats on the same flight. (You cannot pay using miles.)
If an award that has already been reserved is totally unused, all miles used to redeem the award can be refunded to your mileage account by paying the applicable fee.
If you wish to refund, please go to the reservation details.