Unless you pay off your credit card in full each month, you likely have no idea exactly how much your credit card debt is costing you. While some consumers may know that they have a special introductory rate of 0% or 3.99%, most don't know the terms on the regular cards that they use everyday.

And it's not enough to just know the interest rate on your card. You also need to know how that's calculated, what happens to the rate if you pay late, what other actions may cause you to default on your card, what types of fees or surcharges you could incur, whether you have some sort of annual fee, and tons of other details.

Credit card agreements have become so complex that they're not even understandable by the average consumer anymore. I challenge anyone who's been carrying a balance on their card for the last year to calculate for me exactly what their interest charges will be next month. Chances, are, they have no idea. If you have no idea how much you're going to pay for your credit, how can you make an informed decision about whether or not to incur the debt?

The solution to this problem: Don't use credit cards unless you absolutely have to. Pay off your balance in full each month, prior to the due date. Don't get sucked into a credit card trap you can't possibly understand.

Tracy L. Coenen, CPA, MBA, CFE performs fraud examinations and financial investigations for her company Sequence Inc. Forensic Accounting, and is the author of Essentials of Corporate Fraud.