Tricks to avoid

Exactly how might your card company be trying to pick your pocket? Some of the credit-card industry's favorite tactics include:

Hiking the annual percentage rate (APR) on money already borrowed

The good news is that if you receive a letter stating that the terms of your agreement have changed, banks will often give you a way to opt out of the change in terms. The bad news: Usually they do that by letting you close the account to future purchases and pay the balance off under the existing terms.

What you can do

In most cases, card companies must give you at least 15 days written warning before raising your rate, so you'll have time to decide whether to accept the terms or opt out. If you close the account and pay off the balance, you'll lose your card but save the hit your credit score would take if you fought the terms and the card company closed the account with an outstanding balance.

Shortening billing cycles

Shorter cycles make it easier than ever for card holders to inadvertently make a "late" payment. And you not only have to pay more attention to the payment due date; sometimes you have to concern yourself with the hour of day. Last year, the Atlanta Journal Constitution told the story of a Bank of America customer who made a credit-card payment on the due date through his bank's Web site. He was charged a late fee, however, because he paid at 4:10 p.m. instead of by 3:30 p.m.