Delta Airlines offers a frequent flyer program known as SkyMiles. Unlike most other major U.S.-based airlines, the miles accumulated during your travel in the SkyMiles program never expire. If you’re a frequent traveler on Delta or its partner airlines, and you have a SkyMiles account that’s built up enough miles, you can upgrade your ticket to one class higher. For example, you can upgrade an economy class ticket to business class.
Visit the Delta Airlines website and log in to your SkyMiles account. After logging in, your total number of accrued miles appears under your name. To upgrade your seat, you’ll need 5,000 miles if traveling in the continental U.S., Alaska or Canada. Traveling between other countries requires as many as 20,000 miles.
Click on the “My Trips” tab on the side of your SkyMiles page; next, click on the trip you wish to upgrade. Check on the class of your flight to determine if it is possible. If your ticket class falls under "L," "U," "T" or "E," you aren’t eligible for an upgrade with miles. All other classes are eligible.
Select the link by your flight itinerary that says “Upgrade Your Flight,” which will show you the seating option upgrades for that particular flight. Pick the upgrade you want and select “Pay with Miles.” This step completes the upgrade process, and your ticket should now reflect the new status.
Instead of completing the upgrade process online, you can also contact a customer services representative at 1-800-323-2323. Have your SkyMiles account number ready. The operator will walk you through the process of upgrading your flight and provide you with any information you may need.