What is MSISDN (Mobile Station Integrated Services Digital Network)?

An MSISDN is the phone number associated with a single SIM card, in other words, the number you call or send an SMS message to.

The length of MSISDN varies from country to country but is typically 14 or 15 digits long.

It is made up of three elements:

  • Country Code (CC) – 1-3 digits long,
  • National Destination Code (NDC) – identifies the area of a network operator within a country,
  • Subscriber Number (SN) – mobile operator chooses these numbers, which are appended following the CC and NDC.

What is the difference between MSISDN and IMSI?

MSISDN is a phone number, and IMSI is a SIM card identifier, so if you want to change MSISDN, you can use the same SIM card, but to change IMSI, the subscriber must change the SIM card. When calling, MSISDN numbers are dialed, not IMSI.

While IMSI is embedded in the SIM card, the mobile operator assigns the MSISDN when the SIM is registered on the network. Also, MSISDN varies in length, and IMSI has a fixed size.

What does the “+” stand for in MSISDN?

The “+” sign is used as a substitute for 00 when using mobile numbers in international format. There are multiple ways of formatting mobile numbers, and the plus sign is one of the conventions.

Jan 6th, 2022
2 min read

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