Paying your credit card balance on time is crucial to maintaining a good credit score and dodging late fees. However, mistakes happen: 45% of Americans said they missed a credit card payment because they simply forgot, according to a WalletHub survey.

That mistake be costly. Federal regulations currently cap the maximum late fee on a first delinquency at $30, and $41 for subsequent violations.

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But if you typically pay your bill on time, you might be able to get your late fee waived. In fact, almost 90% of Americans who called their credit card issuer were able to do so, the survey found.

Some credit card issuers are more understanding than others, says Ted Rossman, senior industry analyst at Bankrate.com.

“Discover is known for being particularly forgiving,” he says. “They have a published policy that involves waiving every customer’s first late fee. But it’s very common to get out of a late fee with other issuers as well, especially if it only happens once in a while and you’re an otherwise good customer.”

Here’s how to ask your bank to waive a late fee, according to experts.

When calling, have your account number ready. Even though the situation can be aggravating, remember that asking politely gets your further than being irritable, says Matt Schulz, chief industry analyst at LendingTree.com.

“First and foremost, don’t be a jerk,” he says. “Regardless of the ask, you’re much more likely to get your way when you are personable and pleasant than if you aren’t. Of course, you should still be firm and direct, but just remember that you’re dealing with a real person on the other end of the phone.”

If a late or missed payment isn’t a regular occurrence, mention that to your bank, says Rossman. Also add the reason you were late this time and any changes you are going to make to ensure this doesn’t happen. Rossman offered the following script for an example:

“Hi, I’m sorry, I paid my last bill a few days late. I never do that. In fact, it’s the first time I’ve paid late in the 10 years I’ve had your card. I was traveling and missed the due date but I just signed up for autopayments to make sure this doesn’t happen again. Is there any chance you could waive that late fee, please?”

If your payment history isn’t stellar, the chances of getting your fee waived are lower, says Schulz. However, “it is still likely worth asking,” he says.

Contacting your bank can feel scary, Schulz adds, but is often necessary.

“Remember, no one cares as much about your money as you do, so when you have the chance to save some money simply by picking up the phone and asking, you should do it,” he says. “Your chances of success are likely better if you have great credit, but there’s no question that it is not just people with 800 credit scores who get their way, especially when it comes to getting a late fee waived.”