Merchant Category Codes (MCC) are similar to SICs, in that they’re used primarily for identification purposes. But unlike SICs, which were originally determined and developed by the Commerce Department, credit card companies are the ones that assign these four-digit values. In short, while SIC Codes help identify what activities business engage in, MCCs help credit card card issuers identify the types of goods or services a company sells or provides. As soon as a company begins accepting credit as a form of payment for the first is usually when businesses get their MCC affiliation.