I hope you guys are doing that by giving cash discount, instead of charging extra on credit (yeah, I know). That is against both visa's and mastercard's terms of service, and they will go after you for that.
Hm. In North America, the surcharge is against VISA terms of service (linky Canadian government resource below - the terms of services are largely the same within North America). In addition, surcharges are illegal in 10 US states.
