You've probably seen the signs in convenience stores, gas stations and other businesses saying you have to make a minimum purchase to use a credit or debit card.
The minimum amount often varies from $5 to $20, effectively forcing you to buy more than you might need to use your plastic.
Beverly Rouzer of Randallstown said she was recently in a deli near her home when an elderly man attempted to pay with a credit card and was refused.
"I have read in numerous consumer articles that stores are 'not allowed' to require a minimum purchase before you can pay by credit card," Rouzer said. "But obviously, many stores do this. What recourse do you have when the store refuses to budge?"
In the case of the man in the deli, Rouzer said, "He didn't even speak English very well and I wanted to step up for him, but didn't think the cashier would change her mind. Who enforces this?"
Rouzer's absolutely right. Minimum-purchase demands violate credit card merchant agreements.
Visa rules say that merchants should "always honor valid Visa cards in your acceptance category, regardless of the dollar amount of the purchase."
MasterCard says, "A merchant must not require or post signs indicating that it requires a minimum or maximum transaction amount to accept a valid MasterCard card."
Now, neither American Express nor Discover prohibits minimum charges, according to the Better Business Bureau. But both companies prohibit merchants from charging higher minimums for their cards than others they accept. Thus, the BBB says, if a merchant accepts Visa or MasterCard, they cannot require minimum purchases for Discover or American Express.
Some merchants - small businesses, in most cases - demand a minimum purchase because they must pay a fee to process each credit card sale. On small sales, businesses can lose money after that fee.
Nevertheless, such practices are forbidden. Keep in mind that Visa and MasterCard also forbid merchants from charging you a fee when you want to use their card.
Had Rouzer spoken up for the man in the deli, she likely would have encountered resistance or indifference from the cashier. At that point, she could choose to refuse to do business with the merchant to make a point. Or, she could take it to the next level by filing a complaint with the credit card issuer. The bank or issuer could then decide to take some sort of action against the merchant, such as revoking the business' right to accept the card.