The Credit Card Number You Need to Know Now

Do you know your credit card number? No, not your account number. There’s another important number you should know: your APR.

Your APR, or Annual Percentage Rate, determines how much interest you’re charged when you don’t pay off your entire balance during the grace period (usually 25-28 days, or one billing cycle). If you’re not in the habit of paying your card off in full each month, your APR makes a big difference in how much you end up paying for purchases you’ve put on your credit card.

An average low APR card has an interest rate of around 5-9%. High APRs like 29.99% are ones you want to avoid, unless you’re sure you’ll always pay off your card in full each month.

Many cards offer an introductory period where they don’t charge interest at all, on either purchases or balance transfers. These promotional deals often last six months to a year, sometimes longer. It’s not unheard of to have a 0% APR for as long as 21 months.

If your card is charging you more than a 5-9% APR, you might consider looking for another one.

Here are a few other credit card numbers you should know:

Your annual fee. This is the amount you’re charged each year on your card anniversary date. Some cards don’t have an annual fee at all, but if yours does, make sure there’s a good reason. Cards that offer high-value rewards, like travel cards, often charge an annual fee that is worth the price of admission. When you’re getting free airline tickets and hotel stays, paying an annual fee of $65 or even $95 doesn’t seem so bad.

Your credit limit. Every card comes with a limit as to how much you can charge on it. It’s important to know this number, and it’s also important to know another number: 30% of that credit limit. In order to have the best possible credit score, you’ll want to keep your balance to less than 30% of your credit limit. So don’t think of your credit limit as the amount you can spend: think of it as a guideline that you want to never get close to.

Your credit score. Speaking of your credit score, do you know it? More and more card issuers are telling people their credit scores for free these days. It might be printed on your statement, or on your account information online. It’s important to know your credit score and to keep track of it. A high credit score means you’ll be approved for better credit cards, given a lower interest rate when you apply for a mortgage, and maybe even be approved for a more expensive apartment. The best way to maintain a good credit score is to pay your bills on time, not use more than about 30% of your total credit line, have a mix of types of credit, keep accounts open so you have a long credit history, and don’t apply for too much new credit at once.