Merchant Category Code (MCC)

A four-digit code payment networks assign to merchants so issuers know what type of business processed a charge. Your card’s bonus categories (dining, travel, groceries, etc.) depend on MCCs, which is why the same store can earn a bonus on one card but not another, or why some purchases code unexpectedly. Issuers publish category guides, but the MCC on the settlement is what actually drives rewards.