The Big Costco Credit Card Switcheroo

For years, if Costco customers wanted to shop with a credit card, the retail giant required them to pay with an American Express card. But as of Monday, the giant big-box retailer and its 81 million customers are switching over to AmEx's rival, Visa.

Why should anybody care? Well, if you don't shop at Costco, there's probably not much reason. But, if you are one of the millions of Americans who like to buy 12-packs of paper-towel rolls or 30-pound boxes of frozen beef patties, then here's what you need to know:

• Your Costco Visa card should already have been mailed to you. If you didn't get it, Costco says here's what you should do.
• Your old Costco AmEx card won't work anymore starting today — at Costco or anywhere else.
• The rewards points will transfer over to the new card. (Oh, and your balances will transfer over, too.)
• Costco says there are no additional fees related to the switch.
• The new cards won't offer the roadside assistance service that the old cards did.
• Costco says there will be benefits with the new cards — for one thing, 4 percent cash back on gasoline.
• As part of the shift to a Costco Visa card, the big box store will now accept any type of Visa-branded credit card. You don't have to use your Costco-branded Visa card to shop there.

How many people might this change affect? Costco says it has 81 million customers/members who bought $114 billion worth of stuff at Costco last year. By the way, if you ever wondered just how many Costco stores there are in the country and the world, in its latest annual report, Costco says it now has 698 warehouse stores across the U.S., Canada, Mexico, the U.K., Japan, Korea, Taiwan, Australia and Spain.