Minimum purchase for credit card use?

How many times have you popped into the convenience store to grab a snack or something to help your headache and found yourself short on cash? As you handed over your credit card, the clerk pointed to a sign on the register that said you must spend a certain amount (at least $5, for example) to use plastic. Those types of policies actually violate Visa and Mastercard rules, which say merchants can’t require a minimum purchase.

Both companies also forbid stores from charging a higher price to customers who pay with a credit card instead of cash. Yet, the creditors allow a discount for cash. In other words, a gas station can lower its price for cash transaction – but can’t raise it for credit. It’s a technicality.|

Discover and American Express allow minimums, according to a Bankrate.com article, but only if those same regulations apply to any other credit card accepted by a retailer. So in theory, a place that accepts Visa or Mastercard wouldn’t be able to set a minimum purchase amount for someone who uses Discover or American Express. [UPDATE, Dec. 29, 2008 -- A representative of a Web site called www.merchantcouncil.org wrote us to say that Discover does not allow retailers to set a minimum purchase to use its card. Here's a link to their post.]

Thanks Consumer Corner.