If a Square merchant allows customers to pay with cashapp, there is no fee. But if the customer uses the cashapp visa debit card, then the Square merchant would incur the same card fees as any other Visa card. If the Square merchant accepts bitcoin payments, then I believe there are no processing fees until 2027. After that, we’ll have to wait and see. As for whether the merchant “tips” themselves this way, it depends whether they bake the processing fees into their prices or not. Some Square merchants manually add a service charge when paying with paying with cards to cover the card fees.