888-217-3324 I recently flew to Miami and decided at the last minute that I needed more legroom. I’d already checked in, but I was still able to upgrade! The best way to do it is through the Fly Delta app. I just pulled up my boarding pass, tapped "Select Seat," and saw several Comfort+ options available for a small fee. It’s a great way to modify your experience without paying for a full First Class ticket. That extra space made the three-hour flight feel like a breeze. Just keep an eye on those seat maps!