Credit offers advantages over cash or debit purchases. Rewards credit cards let you earn miles, bonus points or cash back and most card issuers offer extra benefits — including protection against fraud, extended warranties on large purchases and the ability to bridge the financial gap if you find yourself facing unexpected bills or expenses.

But there’s also a potential drawback to credit cards: going over your credit limit.

What happens if you go over your credit limit? How is this possible? What are the potential consequences of spending past your limit — and what can do you to fix it? Let’s dive in.

How can you go over your credit limit?

Going over credit limits is only possible if you opt-in. The Credit CARD Act of 2009 stipulates that while credit issuers can allow cardholders to exceed their limits, this can’t happen automatically. Cardholders must agree to this option and sign-off on any associated fees or penalties.

What does this mean for you? If you’ve opted out, your credit card will be declined when you hit your limit instead of allowing you to go over. It may still be possible to exceed your limit if transactions aren’t immediately posted to your account, but if you haven’t opted in for over-limit spending, there should be no associated fees.

If you’ve agreed to allow over-limit purchasing, your card will continue to work — typically until you hit a maximum limit specified in your credit card agreement. Once you hit this limit, your card will be declined.

While exceeding your credit limit isn’t ideal, there are situations where it can be useful. For example, if you need to make a large purchase that exceeds your usual limit, opting in to overspending lets you make a specific purchase without changing your limit in the long-term. You may also go over your credit limit if you need to purchase essentials but are between paychecks — a slight overage can help make ends meet until you can deposit your next check.

On the whole, however, it’s best to avoid going over credit limits whenever possible to limit the potential consequences of spending beyond your means.

What are the consequences?

There are several consequences you may face if you go over your credit limit.

Fees. The most immediate consequence of spending over your limit is a fee charged to your account. This fee will be part of your credit card agreement — the maximum you can typically be charged is $25 the first time you exceed your limit and $35 if it happens again within six months. Worth noting? The fee cannot be more than the amount you’ve gone above your maximum credit. This means that if you go $15 over your limit, you can be charged a maximum fee of $15. Even if you go $100 over your limit, $25 is the maximum fee.

Penalty interest. Some credit providers will also charge penalty interest if you exceed your credit limit. This rate varies, but often hovers around 30% — and applies to the entire balance on your card, not just the exceeded amount. Issuers may also raise your minimum payment to compensate for this higher interest rate, making it harder for you to pay off the excess balance and start using your credit card again. You can often have this penalty rate reduced by paying your minimum balance on time for six months and then contacting your credit card provider directly.

Hit on your credit score. To define your score, one factor used by credit agencies is “credit utilization,” also called “debt utilization.” This is a measure of how much debt you’re carrying compared to how much available credit you have left. To maximize your score, the debt you’re carrying should fall between 10% and 30% of all available credit. If your credit card has a $1,000 limit, that means the balance you carry should be between $100 to $300. If you exceed your available limit, you’re up above 100% debt utilization, which credit bureaus see as a higher risk to default on existing loans and payments. The longer your credit card balance exceeds your limit, the lower your credit score will go.

What can you do to fix it?

The best way to deal with exceeding your credit card limit is to make sure it doesn’t happen in the first place. This means opting out of over-limit purchasing and fees so that your card is declined when you hit your balance. Another option? Sign up for automatic credit limit updates — many issuers now offer email and text reminders of your current balance, and new mobile applications often come with the ability to set a spending limit maximum and get notifications if you’re getting close.

If you’re worried about accidentally going over your maximum, call your credit card provider and ask for a lower credit limit. For example, decreasing the limit on a $5,000 card to $2,500 means that if you do go over your limit, you owe less upfront and it’s easier to pay back your outstanding debt and get your utilization below 100%. It’s also a good idea to check your credit limit regularly, since issuers may raise it without notification.

Once you’ve exceeded your limit, the quickest way to fix the problem is to pay your outstanding balance. Call your card issuer to see if they can waive the initial over-limit fee, and ask about having your penalty interest reduced (or what you can do to have it reduced in a couple months).

What happens if you go over your credit limit? You’ll incur a fee, likely face penalty interest and could see negative impacts to your credit score. Best bet? Opt out of over-limit options and monitor your spending to stay below the limit — if exceeding the limit is unavoidable, have a plan to pay down your balance and get back on track.