It’s hard for us to imagine FFP members letting their miles and flight awards expire, but unaware or disinterested members miss out on thousands of opportunities for free travel. According to the Southwest Airlines 10-K report filed on Jan. 29, 2010, “Since the inception of Rapid Rewards in 1987, approximately 16 percent of all fully earned Awards have expired without being used.” That means around one out of every six awards isn’t redeemed, and that’s not including all the credits that expire when members don’t earn enough for an award within the two-year time frame. Members redeemed 2.4 million awards on Southwest Airlines in 2009, which means approximately 457,000 awards were issued but expired before they were redeemed. As a reminder, Rapid Rewards members automatically earn a free flight award after earning 16 credits within 24 consecutive months and have one year from the date of issue to take the award flight. If your award expires, it can be reinstated and the expiration date extended for another year for a $50 fee.

United Mileage Plus expects 24 percent of its earned miles to never be redeemed, which increased from 15 percent when the airline changed its expiration policy from three years to 18 months. As of Dec. 31, 2008, members had 478.2 billion miles outstanding, and the airline expects 362 billion to ultimately be redeemed. Which means that around 116.2 billion miles will expire from members’ accounts without ever being redeemed, the equivalent in total miles of roughly 4.6 million domestic saver awards in coach.