I booked a JetBlue Blue Basic fare once thinking it would be fine for a quick trip, but I ended up wanting more flexibility and a better seat. I learned that you can upgrade to a higher fare level by paying the difference, depending on availability. I actually did this a few days after booking when my plans became less certain. Later on, I needed to change the flight again and didn’t want to mess anything up. Calling 8 4 4-7 3 4-0 8 1 3 was the best way to instantly book, cancel, or modify flights and make sure the upgrade stuck.
