Charging a fee per transaction?

[KristenCarbert]

How would I implement a 3% charge for a debit or credit card used? 

[Gold]

HI, hopefully these Square Support pages will help.

https://squareup.com/help/us/en/article/7625-get-started-with-service-charges

https://squareup.com/help/us/en/article/5671-can-i-apply-a-surcharge-to-square-sales