Did an email from your favorite airline warn you that your miles are going to expire? Rather than risk losing them, the airline might suggest redeeming those unused miles for premiums as diverse as magazine subscriptions, gift cards and flat-screen TVs.
There are, however, easier and cheaper ways to keep those miles active. Here are nine ways to minimize your toil and trouble or preserve your miles and points:
* Choose the right program and know the policies. Most frequent-flier programs have mileage expiration rules. The notable exceptions are JetBlue and Delta, whose SkyMiles do not expire so you don't have to worry about earning or redeeming miles within prescribed time frames.
If your accounts are with other airlines whose miles do expire, it pays to know their specific policies. American Airlines, for example, extends the expiration date of all your miles 18 months from the date of your most recent activity (earning or redeeming). Alaska requires only that you earn or spend at least one mile every two years.
* Credit-card earning counts. For airlines, the point of maintaining your mileage accounts is to earn or spend miles by flying. If you have your airline's co-branded credit card, the miles you earn by spending on it qualify as account activity and reset your account's expiration date each billing cycle you use it to make purchases.
* Book an award. Redeeming your miles is also considered an activity that will reset the countdown to expiration. If you are sitting on a stash of miles, put some of them to use by booking an award ticket.
* Transfers points. If your airline's frequent-flier program is a transfer partner of another points program, such as American Express Membership Rewards or Chase Ultimate Rewards, or even a hotel program such as Starwood Preferred Guest or Marriott Rewards, transferring those points to your frequent-flier accounts also qualifies as activity and resets the expiration clock. Be aware that you usually need to transfer in increments of at least 1,000 points.
Some large hotel chains also allow you to convert your accumulated points into miles with their airline partners, and that resets the clock too. For example, Marriott has dozens of partners, though the value you get from your points with such a conversion may vary.
* Look for other partners. Airlines often partner with all kinds of companies, not just other airlines, to offer fliers bonus miles for, say, renting cars, booking a hotel or cruise or even changing power or cable companies. Check your airline's Web page on mileage partners to see whether you can earn miles through everyday purchases or transactions.
* Buy miles. Maybe. Buying miles from the airline is a quick and easy way to reset the expiration clock. You can usually buy miles in parcels of 1,000 for around $30, depending on the airline. Although large mileage purchases or transfers generally are not cost effective, a transaction like this can be worth it if you have a lot of miles at stake.
* Shop around. Many of the major U.S. airlines, including American, Delta, Southwest and United, host online shopping sites with links to major retailers such as Bloomingdale's and Target. When you log into such sites with your frequent-flier information, you click on the link to the retailer where you want to shop and you will be redirected to that website.
By completing this extra step, you usually can earn multiple points per dollar on purchases you make on those retailers' sites, which count toward resetting your frequent-flier account's expiration date. What's more, you can spend as little as a dollar on something -- a song from iTunes, perhaps -- and that activity will take care of your expiration conundrum.
* Dine out. Several of the major airlines also partner with Rewards Network, a company that fields a huge network of affiliated restaurants. To participate, log onto your airline's affiliated Rewards Network site (you can usually find the link in the airline's information page on mileage partners), set up an account and link it to one or more of your credit cards.
When you eat out and use that credit card to pay for your meal at one of the participating restaurants, you can usually earn three to five bonus miles per dollar and refresh your mileage account to boot.
* Call and ask nicely. Have your miles already expired? It never hurts to call an airline's frequent-flier desk and ask nicely whether those miles might be reinstated. Most airlines will charge a one-time fee -- from $50 to thousands of dollars -- but agents sometimes will waive it.
Alaska Airlines recently did this for me, not only rebooting my inactive account but also re-crediting it with the 2,001 orphan miles in it that had expired. All it took was a two-minute phone call.