Q. My father is turning 75, and all of a sudden, two of his credit cards have sent him letters closing his accounts. He has never missed or been late on a payment. Are they discriminating against him because of his age?

A. Probably not. Credit card companies are slashing limits and closing accounts for customers of all ages, even those who've never missed a payment. American Express has gone so far as to pay cardholders $300 to close their accounts.

The companies are targeting customers based on where they live, how they make their living and how big of a balance they carry. And they're willing to accept far less risk than they were just a few years or even months ago. So they're ditching accounts that pose too much risk or that don't generate an acceptable level of profit.

We haven't heard of cards targeting customers by age. Indeed, we've usually heard from younger customers who've had their credit limits slashed or their accounts involuntarily closed.

According to Meredith Whitney, the Wall Street analyst who became famous for predicting the current banking crisis, there's about $5 trillion worth of credit currently available on the nation's credit cards. We've used about $800 million of that.

Those credit lines were reduced by about $500 billion in the final three months of 2008, and by the end of 2010, Whitney expects the amount of credit available to consumers on their cards will be down to about $2.3 trillion.

In this environment, it's almost impossible to persuade the credit card companies to rescind a decision to close an account. But with your father's solid payment history, he can apply for a new card. (Yep, the companies throwing customers out one door are bringing them in another.)

Our extensive database of credit card offers is a good way to get started and compare rates, benefits and fees.