Anyone would jump at the chance to move from economy to a higher class of service when flying, and Delta makes it easy (and free) to do so with its Regional and Global Upgrade Certificates.

American Airlines lifetime members and high-tier elite members can earn systemwide upgrades. Here's how to earn and use these valuable upgrades.

Get the scoop on how to use United Airlines’ PlusPoints to boost your seat to a premium cabin. Learn how to earn, find upgrade-eligible flights and make the most of your travel rewards.

Use miles to upgrade a paid ticket from economy to business class, or business to first class.