There is almost certainly nothing legally to prevent them from taking cash. The idea is simply (probably) to get them to say they only take credit cards. Obviou

There is almost certainly nothing legally to prevent them from taking cash. The idea is simply (probably) to get them to say they only take credit cards. Obviously they will take cash if the person only has cash and insists. They post that they don't accept cash and if someone doesn't see that they will take cash and Visa will be fine with it (where 'fine' means they will look the other way). It's the golden rule. He who has the gold rules. [1] The one with the balance of power wins. [1] Let's say in the normal course of business you are owed $5000 and have been trying to get a deadbeat customer to pay for a year. It's obvious that you don't want to get paid in pennies. In this case the customer says 'I will pay you but it has to be pennies'. What would anyone do? Accept the pennies.