Availability of upgrade seats depends on demand for full-fare premium cabin tickets. As a result, upgrades may not be available for every flight. Keep in mind that many premium cabin bookings do not occur until a week or two before departure, so upgrades may not become available until as late as the day of departure.

If an upgrade is not available at the time of your request, you will be placed on a waiting list. If upgrade seats become available, they will be assigned based on Mileage Plus status and booking class, so those factors will also affect your likelihood of receiving an upgrade.

To find out if you have received an upgrade, you can check the status of your request through My Itineraries. If your requested upgrade has not been confirmed by the time you check in for your flight, you will be placed on the upgrade list, which is also prioritized based on Mileage Plus status and booking class. Any remaining premium seats will be assigned at the gate, according to the upgrade list.