by Alison Storm | 04/7/10

Airline miles, cash back and shopping discounts are just a few of the perks credit card companies can offer. While those perks may entice you to sign up with one credit card company over another, make sure you know exactly what the company is offering. While new credit card regulations are in place, those do little to protect you from losing out on rewards if it's in a company's policy. Here are three things to watch out for:

Expiration Dates: Rewards almost always expire. According to the New York Times, Bank of America and Citi give users five years to use their points. No one really knows how many rewards go unused, but market research shows that only one out of four cardholders redeemed points in the past year.

Late Payment Penalties: If you're late on a bill twice, that can wipe your rewards clean if you use a Discover card. Other companies only cut the rewards earned during the billing cycle of the late payment. With American Express, if you're late on a payment you may have to pay a $29 reinstatement fee to get back any points you lost because of being overdue on your bill.

Transfer Rules: A great feature of rewards is being able to transfer them to friends, family members or charities. Sometimes there is a transfer fee of one cent per mile, meaning it would cost $100 to transfer 10,000 miles. Your credit card company may also have caps on how many miles you are allowed to give or to receive. Bank of America currently does not charge for transferring points when you are moving between 2,500 and 25,000 points.