Credit cards can be excellent tools for building credit, and they enable you to make larger purchases that you might not be able to afford right away if you were just working with cash. But they can also turn into a nightmare if you end up carrying a balance.

The average credit card interest rate is about 17%, but some can get as high as 36%. If you owe $1,000 but you can only afford to pay $50 per month and your interest rate is 36%, you'll end up having to pay $550 in interest, and it'll take you more than two and a half years to get that debt paid off.

Many people think there's nothing they can do about this, but they're wrong. If you've been a good customer, many card issuers will be willing to lower your interest rate if you just call and ask. Here's a quick guide on how to negotiate a lower credit card interest rate.

Man looking at smartphone.

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Be realistic

The first step is to look at your current situation and try to see your request through the eyes of the card issuer. Most will be willing to work with you because they don't want to lose your business to another company, but you have to be reasonable. If your current credit card charges a 36% interest rate, you shouldn't expect them to drop it to 12%. That's just too big a cut.

You can get an idea of what a fair interest rate would be by looking at the credit card offers you're receiving in the mail. When you call to negotiate a lower rate, you can use this information as leverage to assert why you deserve it.

You also have to give some thought to your current credit situation. If you owe a lot and you've missed payments before, credit card companies are less likely to be accommodating than they would be if you've always made your payments on time. If you fear that your credit score could hurt your chances of getting a lower rate, do what you can to pay down the debt and bring up your credit score before you request a lower interest rate.

Be polite but persistent

Call the credit card company and lay out your case. Tell them what rate you're looking for and that you are thinking about closing your account if you don't get it. If you've had the card for a long time, highlight your loyalty as another reason you deserve a lower interest rate.

Be polite, even if the representative denies your request. Shouting at them or getting angry will make it even less likely that they will change their mind. Instead, if your request is denied, ask to speak to a manager. A manager might have greater authority to make decisions about interest rate changes.

Don't give up

If the manager still denies your request, all hope is not lost. Try working on building up your credit and paying down your debt and then call back with your request in a couple of months. Or you can try transferring your debt to a different credit card and closing the account.

When choosing a balance-transfer credit card, you want to make sure that it offers a 0% introductory balance-transfer rate for new cardholders. You'll also want to pay attention to any fees associated with transferring the balance. Often, you might be charged a small percentage of the balance you're transferring. Take a look at the standard interest rate as well. If you can't pay off the full balance of what you owe within the introductory period, you'll end up accruing interest on it at the standard rate, so you want to make sure you're not going to end up worse off.

Of course, the best strategy is to avoid carrying a balance altogether. Then the interest rate on your credit cards won't matter at all. But this isn't always possible. In that case, following the steps listed above is a good way to get your debt under control.

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