MCC, MNC and PLMN explained

Every SIM card and every mobile network carries a short numeric identity. This page covers how those numbers are built and how a phone uses them. For one-line definitions and who assigns the codes, see the FAQ on the home page.

How an IMSI is built

A SIM stores an IMSI (International Mobile Subscriber Identity) of up to 15 digits. Its first digits are the network's PLMN and the rest identify the subscriber:

310 260 123456789
 |   |        |
MCC MNC     MSIN (subscriber number)

The MCC + MNC pair is the PLMN. Looking up 310-260 in the database tells you which operator issued the SIM.

Two-digit and three-digit MNCs

The MNC length depends on the country's numbering plan: North American networks use 3-digit MNCs, most of Europe uses 2. A leading zero matters — 01 and 001 are different codes — which is why this site keeps MNCs as written in the ITU bulletins.

Countries with more than one MCC

Large markets may be assigned several country codes: the United States has 310 to 316 and the United Kingdom has 234 and 235. Some codes (such as 901) are not tied to one country at all. Use the MCC list to see every code and the country it belongs to.

How a phone uses the PLMN

• Network selection: the phone compares the PLMN broadcast by nearby cells with its home PLMN and a list of preferred roaming partners.
• Roaming: when the visited PLMN differs from the home PLMN, the visited network routes authentication back to the home operator identified by the MCC and MNC.
• MVNOs: virtual operators usually share a host network's PLMN or hold their own MNC, so one brand can map to several codes and one code to several brands.

Look up a code

Search the full database, browse the MCC list, or use the API to query codes programmatically.