What does it cost a merchant to accept a credit card?

For small businesses it costs about 35 cents to swipe a card and then you can about 2% of the purchase price. So for a $10 purchase it would cost them about 55 cents. For a debit card it is usually a flat fee of about 65 cents. On big purchases a merchant would rather have a debit card pay for the transaction. I am assuming these fees are significantly less for very large businesses.