In the US, it is illegal to charge customers a fee for using their credit card. Whether it is or not in Thailand, the standard practice in Patong is to charge 3% (if they even accept a credit card at all)! I even had a restaurant charge me 4% for using a credit card. Even my hotel tacked on an additional 3%! The only place that didn't charge me an extra fee was the dental clinic but I am sure it was factored into the price. :(
Another interesting fact is that one business will have a credit card processing machine and several neighboring businesses will use it. I am guessing they share the rental cost of the machine. For example, I ate at a restaurant and afterwards handed the waitress my credit card for payment. A few minutes later, a man with my credit card appears at my table and says, follow me. We go down the street about a block and into a tailor shop where my credit card is processed. This type of situation happened several times.
