Your clients may have a way to get their credit card company to lower its interest rates: Just ask.

A simple phone call is all it takes for many consumers to save money on their monthly credit card payments, according to a survey by

Two-thirds of cardholders who asked their credit card companies for a lower interest rate said they got it, according to the survey released Thursday. Likewise, 60 percent of those who asked that a penalty be waived for a late payment had the charge eliminated.

People in their peak earning years have the best chances of getting the breaks on fees, according to the survey.

Of customers between the ages of 30 and 64, 89 percent who asked for late penalty forgiveness had their request approved. Only 16 percent of 18- to 29-year-olds and 13 percent of those 65 and over got the same treatment.

Likewise, credit card holders with full-time jobs were given late payment forgiveness 25 percent more often than adults who were employed part-time or unemployed.

"A lot of people who've had accounts for a long time have probably earned a better rate than they're getting due to establishing a good credit history, but the creditors won't check unless the cardholder calls and asks," said Melinda Opperman of Springboard Nonprofit Consumer Credit Management.

If a customer’s credit score justifies a lower rate, a credit card company will lower the rate if asked, she added.  

As a cautionary note, she said, asking for a lower rate could lead to a credit check, which could adversely affect the customer’s credit score.

The survey, conducted from July 17 to July, took data from nearly 1,000 consumers who held American Express, Visa, MasterCard and Discover credit cards.