How to upgrade on United?

Passengers with regular-class flight tickets on United Airlines can use the upgrade options to move to the next higher-class cabins. The airline provides several methods for requesting an upgrade, such as using miles, placing a bid, or paying cash during check-in. The United Airlines Upgrade flight option can be used while booking the flight or after the booking is confirmed. For more detailed information on the upgrade process, one can contact United Airlines customer service or read the blog by Airlines Group Travel.