MCC

A three-digit number that identifies the country of a mobile subscriber. It forms the first part of the International Mobile Subscriber Identity (IMSI) and works together with the Mobile Network Code (MNC) to ensure that subscribers are uniquely identifiable on mobile networks worldwide.

An MCC is standardized by the International Telecommunication Union (ITU) and is essential for routing calls, handling roaming agreements, and distinguishing national operators. For example, when a device connects to a network abroad, the MCC immediately signals which country the subscriber belongs to, allowing local carriers to authenticate and route communications properly.

The MCC is only meaningful when paired with an MNC, but by itself, it already provides a crucial layer of geographical context in the structure of mobile communications.