In Texas, a merchant cannot charge a customer for using a credit card. However, a merchant can give a customer a discount for using cash.
Here is some information from the Texas Attorney General's website:
"In Texas, a business cannot penalize consumers who pay for a good or service by using a credit card. Businesses that add a surcharge to those who pay by credit card might be violating provisions of the Texas Finance Code. Usually those fees can only be charged by government entities, such as for the payment of property or other taxes or other fees required by a government agency.
However, businesses in Texas can discount the regular retail price of an item for consumers who pay cash instead of using a credit card. Consumers who are charged extra for using a credit card should report it to my office by calling us at 1-800-252-8011 or filing a complaint online at www.oag.state.tx.us.
Similarly, businesses that accept credit cards are generally forbidden from setting a minimum amount to be charged to the card. While there is no law that prohibits this practice, virtually all agreements that merchants have with credit card companies prevent the business from imposing a minimum charge for card users. If you are faced with this, report it to your credit card company."
If you would like more information about credit card use in Texas, here is the Attorney General's website: http://www.oag.state.tx.us/agency/weeklyag/weekly_columns_view.php?id=63.