If you plan on swapping a block of miles that you currently have for miles that you need on another airline, the process is fairly simple and straight forward. It is always best to check with the airline’s frequent flyer program for the fees and guidelines, but as a rule of thumb, it costs approximately $10 per 1,000 miles plus a service fee that is usually $30.

For example, if you have 90,000 miles on United and need another 10k to reach a 100k 1st class ticket, you would do well to trade with another party that has the 10k United miles but needs the 10,000 Delta miles to top off their account. The trade is a win-win. You transfer 10,000 of your extra Delta miles to someone that transfers 10,000 United miles to you.

The airlines make a few $ on the trade, but you both benefit by reaching your goals.