https://www.theverge.com/2019/9/20/20876570/paypal-refund-fe...
Square still refunds processing fees to merchants for refunded transactions. They have the same fee (2.9% + $0.30) for online transactions, and a lower fee (2.6% + $0.10) for in-person transactions with their card reader.
https://squareup.com/help/us/en/article/5060-refund-overview
