American Airlines has different levels of cabin classes, so if you booked your ticket with its lower cabin class and want to upgrade your flight to its upper-class cabin. Then, the airline allows you to upgrade the seat, and it offers four different ways to do so. Travelers can upgrade their flight using options such as using AA Upgrade with Miles, SWUs, complimentary upgrades, or the airline’s small-business program. To find out more details related to the upgrade, visit the official website of American Airlines or read the blog at the mentioned link.