[crazygringo]

Interestingly, in 2013 both credit card minimums (up to a maximum of $10) and surcharges (up to a maximum of 4%) became legally federally, although there are 10 states that still prohibit surcharges (including New York, California, and Texas).

So seems like $0.35 is allowable on any transaction of $8.75 or more.

[1] https://www.thebalance.com/credit-card-surcharges-315423

[velosol]

I think it's also worth noting that many of those states allow cash discounts.

https://www.ncsl.org/research/financial-services-and-commerc...