Yesterday, FatHeadDog’s chief financial officer (husband) opened the mail to find correspondence from American Express that they’re raising our credit card interest rates, with an explanation that sums to “that’s the cost of doing business.” My off the bat response–”Let’s call and ask them to lower it. If not, see ya later American Express.”

If you didn’t already know, you can call your credit card companies to ask for a lower rate. In fact, more than 75% of people who call to ask for a lower rate are successful on the first call, according to financial author David Bach in his new book “Fight for Your Money: How to Stop Getting Ripped Off and Save a Fortune.”

Here’s how: Take any of your credit cards that are carrying a balance, flip them over, and call the number on the back. Tell them that you want an interest rate reduction or you’ll take your business elsewhere. Before you call, know the rate you’re currently paying and the kind of rates that other banks are offering. (Bankrate.com is a great source for comprehensive lists of interest rates from credit card companies across the country.)

If the first person you talk to won’t do it, ask to talk to a supervisor. Be aware that there are often many levels of supervisors, so if the first supervisor doesn’t give you what you request, ask to speak to that supervisor’s manager.

Even if the credit card lords are only able to shave off a few points from a high interest rate, it will make a difference. If you have a $5,000 balance, even a 3% rate reduction saves you $150 a year.

What happens if they won’t negotiate? Ask to have the account closed. This will trigger a transfer to the customer retension department–the final stop of customer service whose job is to talk customers out of canceling their accounts. It’ll likely work, and once you get one card down, I bet you’ll find it such a rush that you’ll press onward for all your cards. No? Just me?