A couple of years ago, I got a nasty surprise: my hard-earned JetBlue (www.jetblue.com) miles had "expired" due to "inactivity" in my account. It happens to thousands of people every year, usually with no warning.
Keeping track of the airlines' policies concerning the expiration of frequent-flier miles is a full time job. And while Delta Air Lines (www.delta.com) and Alaska Airlines (www.alaskaair.com) miles don't expire for now (that is, unless the member expires first, most airlines will wipe out your account if it's inactive for 12 to 18 months.
There are some exceptions: British Airways (www.ba.com) points expire after 36 months. Air Canada's (www.aircanada.com) miles expire after 7 years, whether or not there's account activity. Spirit Airlines' miles (www.spirit.com) now expire after a paltry 3 months of inactivity. True, some airlines let you re-activate expired miles, but it will cost you.
But for most airlines, there's absolutely no excuse to let your miles expire, even if you don't fly or don't have an airline-branded credit card. You probably already do things that could earn you extra miles (and protect the miles you have) -- if only you knew the possibilities.
Do you make charitable donations? You could get bonus miles and extend your current miles for doing so. Planning to sign up for Netflix (www.netflix.com)? Don't do it without going through your airline's website. About to have your taxes done by H&R Block (www.hrblock.com)? Do it through the US Airways (www.usairways.com) website, and you'll get 4 bonus miles for each dollar spent. Even a 99-cent iTunes (www.apple.com/itunes) purchase will earn you two Rapid Rewards points over at Southwest Airlines (www.southwest.com), extending your points for another 24 months.
Here are the top ways to add activity to your account without flying and without using an airline credit card.
1. Dining for miles
Although the restaurants participating in the airlines' dining for miles programs may not be Michelin-starred establishments, there's probably at least one spot near you that you'd be happy eating at. In addition to generous miles-per-dollar awards, there are sign-up bonuses. For example, American (www.aa.com) and US Airways (www.usairways.com) offer 1,000 miles after your first meal.
Do you shop? Of course you do! But if you're not getting bonus miles, you're throwing good money away and failing to protect your frequent-flier account. More than 400 online merchants -- Walmart, Drugstore.com, PETCO, JCPenney, Ann Taylor, Nike, and on and on --participate in the airlines' shopping mall programs. Even if you don't use an airline credit card, you'll get anywhere from 1 to 12 bonus miles for each dollar spent (sometimes more). And while it used to be that you had to shop online to get the miles, increasingly merchants such as Sunglass Hut are offering miles even for shopping in store or by phone. Here are links to the airlines' malls.
3. Renting a car
Never rent a car without giving the rental agency your frequent-flier number. You needn't fly in order to get the miles. Just be aware that you might pay a small fee for collecting the miles.
4. Staying in a hotel
Most hotel chains participate. Stay in a hotel, give your frequent-flier number when you make the reservation or check in, get new miles, and protect the miles you have. (Some discounted hotel rates don't qualify for miles, so check before you book.)
5. Sending flowers
Valentine's Day looming? Mother's Day? Just because? You'll get 20 United (www.united.com) miles per dollar at FTD Gifts and Flowers. Most other airlines participate.
6. Taking a cruise or vacation
Airlines offers big mileage bonuses on cruises and vacations when you book through their sites.
Transfer $100,000 into a Fidelity (www.fidelity.com) investment account, and you'll get 50,000 United miles; $25,000 earns 15,000 miles. TDAmeritrade (www.tdameritrade.com) offers up to 25,000 miles for a new account. Other airlines offer similar perks.
8. Taking out a mortgage
9. Signing up for Netflix
Other airlines participate. Planning on extending your Verizon or AT&T Wireless contract for another two years? Do it through your airline's website and get bonus miles.
10. Donating to a charityGive to the USO, UNICEF, or cancer research (up to 10 miles per dollar donated), and you'll get American's AAdvantage miles; you might help save lives, plus extend the life of your own miles.
Click here for a chart showing the airlines' mileage expiration policies.
George Hobica is a syndicated travel journalist and blogger whose website, www.airfarewatchdog.com, tracks unadvertised airfare wars and fare sales, including the most helpful and always updated Top 50 Airfares.