MCC (Mobile Country Codes) are used in Wireless Telephone Networks (GSM, CDMA, UMTS, etc.) to identify the country which a mobile subscriber belongs to.
An MCC is used in combination with an MNC (Mobile Network Codes) (a combination known as an “MCC/MNC tuple”) to uniquely identify a mobile network operator (carrier) using the GSM (including GSM-R), UMTS, and LTE public land mobile networks. Some but not all CDMA, iDEN, and satellite mobile networks are identified with an MCC/MNC tuple as well.
The combination of MCC and MNC tuple is called HNI (Home Network Identity) and is the combination of both in one string, for example: MCC= 404 and MNC = 58 results in an HNI of 40458 for BSNL in India.