We’re all trying to be a little more frugal these days, so it’s smart to use financial reward programs when we can. If you’re a frequent flier, and have earned miles, it’s important to know that your miles can expire and render your hard earned savings useless.

According to the Wall Street Journal, approximately 20 percent of air miles go unused, so the newspaper has put together a detailed report of how you can do your best to salvage these precious miles.

Here are a few tips:
Keep your miles “fresh” by signing up with a company that offers rewards not only through flying, but through shopping with its partners. Some airlines let you gain points by making purchases at grocery stores, hotels, car-rental companies, and other partner airlines.

Pay attention to other non-travel related ways you can earn miles. Some airlines even let you subscribe to a newspaper or magazine for a few thousand miles toward your credit.

Update the airline with your email address if you ever change it.

Sign up with web services that allows you to track your miles and their
expiration date. The WSJ suggests AwardWallet.com, which is free.

Here are a few US airlines and their expiration policies.

Airlines that expire miles after 24 months of no activity:
Delta
Alaska
Southwest (credits good for 24 months)

Airlines that expire miles after 18 months of no activity:
American
United
Continental (may cancel the account after 18 months)
US Airways

Airlines that expire miles after 12 months of no activity:
JetBlue
AirTran (credits good for 12 months)

© Cheapflights Ltd Andrea Mooney