MSISDN

MSISDN is a number uniquely identifying a subscription in a GSM or UMTS mobile network. Simply put, it is the telephone number to the SIM card in a mobile/cellular phone. The abbreviation has several interpretations, most common one being "Mobile Subscriber Integrated Services Digital Network Number".

The MSISDN together with IMSI are two important numbers used to identify a mobile phone. IMSI is often used as a key in the HLR ("subscriber database") and MSISDN is the number normally dialed to connect a call to the mobile phone.