Minimum purchase requirements for credit cards

Do you know companies are not allowed to require a minimum purchase for Visa or MasterCard transactions? I learned this yesterday after a disappointing experience at my local produce market (conveniently called "Produce Market"). I drive by it nearly every day and often tell myself to go in there and load up on fresh fruits and vegetables. Yesterday, I finally got around to it and dropped in.

What I liked
They did indeed have a great selection of fresh produce and reasonable prices. The store had a straight-forward layout and was very easy to quickly navigate. I was feeling pretty smart as I browsed their selections since I had finally made the decision to do some shopping there.

A Heaping Dose of Surliness
Apparently, customers must accept a heaping dose of surliness in exchange for that fresh produce at low, low prices. The two employees I encountered were unfriendly and declined to say "Hello", "Good Morning", or offer any other form of commonly-accepted salutation, even after I said "Hello" to them.

What I did get was a scolding from the cashier who rang up my $7.98 sale. I handed him my credit card and he pointed to a sign that said "$15 Minimum Purchase Required for Credit Card Transactions". "I'll let you use your credit card this time, but please remember a $15 purchase is required to pay with a credit card in the future."

That Rule Is Against the Rules
My encounter at Produce Market left me a bit disappointed, but also curious about those minimum purchase requirements. These policies are very unfriendly to customers and I had heard they may actually be a violation of the merchant agreement with Visa and MasterCard. So, I looked it up and yes, these policies are a violation of the merchant agreement.

Visa
You can verify the rule for yourself on this page of their website.

MasterCard
They bury this information on page 2-22 of their merchant rules manual, but they do offer a handy complaint form you can use to zing your least-favorite non-compliant merchant.