UPDATE: Recent changes in the law have altered the landscape for minimum purchase requirements. As MasterCard explains, "A merchant located in the United States or a region/territory of the U.S. may set a minimum transaction amount for credit cards only. The amount may not exceed $10 (U.S. dollars) and cannot discriminate between issuers or between MasterCard and other acceptance brands. Merchants are not permitted to require a MasterCard cardholder to pay a minimum amount in a Debit MasterCard or MasterCard prepaid card transaction."
So the new threshold is $10, meaning if a convenience store says no cards under $20 they are violating the credit card company's terms. And a minimum amount on any debit card is still prohibited.
For example, when you walk into a convenience store and they say, "We don't accept a credit card for purchases under $15" this is designed to get you to buy more stuff to reach that threshold, or because they don't like the interchange fee they pay when processing credit cards... in which case they should negotiate a better deal with the credit card processor, improve their profitability, or just not accept cards at all.
In any case, it is NONE of your concern. You are a customer and should be allowed to use your credit card if they accept them.
Tell them, politely of course, that they are in violation of their merchant processing agreement. If they still fail to ring up your items, contact VISA or MasterCard about this. Both of those credit card brands prohibit such practices, in addition to Discover.
You should be allowed to use your VISA debit or credit card regardless of whether the purchase is for $18 or $80,000.
American Express does not prohibit such minimums, but discourages them because it is bad for the cardholder experience.
If you get cash back rewards or air miles when you make everyday purchases, you should be adamant about using your card everywhere you go. Plus, using a credit card provides additional warranty protection in many cases and provides greater protection against fraud.
UPDATE 2: Since this article was written several years ago, card acceptance at gas stations has changed as well. Some stations will post a "credit price" and a "cash price" for their fuel, offering a slight discount to those who pay with cash versus plastic. I don't see this going away any time soon.
You'll have to calculate whether the lower cash price outweighs the points or miles you'd accrue by using your card at the pump.
Onward and upward. And be sure to check out this week's hottest credit cards on Outlaw, as ranked by cardholder reviews and rewards offered. We've noticed a recent trend toward balance transfer cards since March, which makes sense, as some issuers in our deals system are now offering up to 18 months of 0.00% introductory APR on approved transfers.
Air miles cards continue to be another popular area for our users, due to the lucrative summer sign up bonuses offered. Make sure to avoid any card where the annual fee outweighs (or marginalizes) the air miles bonus offered.
Photo Credit: orphum / Flickr