As part of your plan for learning how to build credit, you might wonder if you should start closing credit card accounts. After all, if you have more than five credit cards, you have more than the ideal number. (Read the post called, “How Many Credit Cards Should I Have?”)

True, credit scoring systems are happiest if you have no more than five credit cards. But before you make that call to the credit card company, be aware that closing credit card accounts can have a major impact on your credit score. Keep in mind a few basics about owning credit cards.

Fifteen percent of your credit score is derived from the age of your credit accounts, with older credit accounts giving you a better score. This part of your credit score is based on the average age of your accounts. As a result, every time you terminate older accounts, you drive down the average age of your accounts considerably and risk decreasing your credit score.

You should also consider how closing credit card accounts will affect the portion of your credit score that considers your credit card limits and balances. Your “utilization rate” is the ratio of your credit card balance against your credit limit, expressed as a percentage. If you have $800 of debts on a credit card and your available line of credit is $2,000, your utilization rate is 40 percent. Since credit-scoring bureaus reward people who have utilization rates below 30 percent, you should try to always keep your utilization rate under that threshold.

Closing credit card accounts can impact your utilization rate in a couple of ways. First, if you decide to cancel a credit card and transfer the remaining debt to another card, you may cause the utilization rate on the second card to rise sharply, which will cause your credit score to drop. Even worse than transferring a balance is leaving a balance on your card after canceling the account. If you leave a $700 balance on the canceled card, your utilization rate will suffer dramatically since the limit on the card will be $0.

So what is the plan for dealing with a bunch of credit cards? Even FICO agrees that closing credit card accounts is a bad idea. Your best bet is to keep all of them active but pay them off every month. You can even find ways to live debt-free and keep your credit cards active. A steady history of payments will demonstrate to credit-scoring bureaus your ability to manage your accounts and will eventually improve your credit score. Pay special attention to the cards with the highest limits, oldest ages, and best interest rates. Be sure to keep these cards active, maintaining a utilization rate below 30 percent.

A final note: Retail credit cards (those associated with a specific store, such as Bloomingdales) are an exception to the “keep-them-open” rule. Keeping a balance on these cards may be difficult since you probably do not need to buy something from these stores each month. Letting a retail account go inactive may not be the ideal choice, but it should not be a cause for alarm unless it causes your credit score to drop, in which case you might be able to reactivate the card with a simple phone call.

Closing credit card accounts isn’t the only thing that will hurt your credit score. If you want to learn more about how to improve your credit score, be sure to check out our free teleseminar.