A cash discount is when you post credit card prices and offer a discount on that price for customers who pay with cash.
The “posted price” refers to prices posted on shelves, menus, or in advertisements.
Compliant cash discount programs must increase the posted price listed on the shelf and then reduce it at the register when customers choose cash.
A surcharge is when you advertise or publish a cash price and charge an additional fee on top of the advertised or published price. This surcharge can only be applied to Credit Card sales only.
In the first situation, a customer pays less than the advertised or published price. In the second case, a customer pays more than the advertised or published price when paying by Credit Card.