It is usually a good idea to close most unused credit accounts, especially if you are planning on applying for a large loan like a mortgage. Lenders check your report not only for positive payment history, but also for “potential debt.” Even though you owe nothing on the card now, you could—in theory—max out this card the day after a lender grants you a loan and suddenly be unable to pay all of your debt. So, most lenders actually view this available line of credit as indication of higher credit risk.

However, you also want to make sure you have enough credit for an emergency. It’s a good idea to keep one card that you regularly use and an additional one or two other cards (with the best interest rates) available for an emergency. If you have more cards than that, it will probably be in your best interest to close them so your credit report accurately reflects the amount of credit you intend to use.