The method of booking a flight with frequent flyer air miles may differ among various airline companies. United Airlines allows its MileagePlus members to book flights using their award miles directly through the website of the company, as of 2015.
The MileagePlus award miles can be used to book flights on United or any of the other StarAlliance carriers. In addition, the award miles can be used to upgrade an existing reservation, which can also be done through the website.
The American Airlines website has a similar function where AAdvantage members can use their award miles to book flights online. The company also allows award travel to be booked over the phone, although as of February 2015, the company charges a fee for any phone bookings that could have been made on the American Airlines website. The fee is $30 for flights within the United States and $40 for international destinations.
AAdvantage award miles can be used to book flights on American Airlines, American Eagle or any oneworld airline. Customers can use the Award Map on the American Airlines website to see exactly where they can travel based on the number of miles they have. They can also use the miles to book hotels, rental cars or upgrade a flight to business or first class.