Note (2019): Square's per transaction fee for card payments that are dipped, tapped or swiped is 2.6% + 10c. Learn more in our Support Center.
The prohibition of adding surcharges in California of which you mentioned has been ruled unconstitutional as of March 2015. See this link: https://oag.ca.gov/consumers/general/credit_cards.
However, what I believe you can do (even in California) is set a price that takes the added surcharge fee into account as your published price, but then offer a "discount" price for cash-paying customers, like many gas stations do. Square lets you set a discount amount or percentage on your dashboard. To calculate the price based on surcharge overhead, simply do the following computation: X = Y/0.9725, where X is the price you would charge the customer and Y is the amount you expect to collect from the credit card vendor. As you will see, the numbers consistently add up correctly (rather than using the 2.83% estimate). To set the discount on the dashboard, simply enter 2.75% and use it whenever patients pay cash. Beware of other laws, such as deceptive pricing laws, etc. And ALWAYS make sure your pricing policy is clearly posted or noticed in your place of business.
