| Most of the merchant agreements do NOT allow for a business to pass on their service charges. You need to check out the agreement. I just got into a major hassle with a Dairy Queen that was charging me 75 cents for a $4 blizzard. The local owner was a ditz. I usually just let things go (I used to own retail stores of my own); but I ended up calling corporate on this rude, obnoxious owner. There were no signs up, etc. And when I said I bet you it isn't legal, he insisted I was the idiot. After the conversation with corporate, I got the satisfaction of having the guy call me to apologize and admit that I was right.
In any event, it is all dependent on the individual merchant agreement signed between the retailer and the provider. | 
