What is MSISDN?

MSISDN stands for Mobile Subscriber Integrated Services Digital Network-Number. It is a number the identifies a unique GSM or a UMTS mobile network subscription. In other words, MSISDN is the telephone number to the SIM card in a mobile/cellular phone.

What is its importance?

Due to the increased incidence of fraud, MSISDN can be used for an effective control and monitoring as well as for tracking. Together with IMSI, MSISDN are two important numbers used to identify a mobile subscriber.

IMSI distinguishes the SIM while the MSISDN is utilized for connecting calls to the subscriber. IMSI is usually used as a key in the HLR or the subscriber database and MSISDN is the number used to dial to route a call to the mobile phone.

How would I know that I am looking at the right MSISDN?

An MSISDN is limited to 15 or 16 digits. To help you identify them correctly, here are the formats:

In GSM and its variant DCS 1800:

In the GSM variant PCS 1900:

Example of MSISDN:
MSISDN: +917207775621

CC = 380 Ukraine
NDC = 56 Dnipropetrovsk
SN = 1234567 Subscriber's number