Payment card networks couldn’t assign a specific merchant category code for firearms retailers under
Merchant category codes are four-digit numbers set by the International Organization for Standardization to help organize businesses by the types of goods or services provided, such as grocers and restaurants.
Payment networks such as Visa and MasterCard use MCCs to determine consumer rewards and risk-related fees, and help with fraud prevention and tax reporting. For instance, sporting goods retailers — many of which sell firearms at their stores — ...