In my case, a man came in with a large framing order for his large home. At time of down payment, I was presented with a corp. card. I knew that the fees would be higher, but was blindsided when I got my statement at 5%. The fee was a combination of my regular discount rate, plus the corp. fee. Yes, the interchange fees are charged to the cc processor, but they are passed on to us merchants. If there are any out there that dont pass these fees on, I want to know about them.