What is MSIN Mobile Subscriber Identification Number

Technical details of the Mobile Subscriber Identification Number (MSIN).

1. Definition and Purpose:
   • The MSIN is a 10-digit unique numeric code used by mobile network operators (MNOs) to identify individual mobile subscribers within their network.
   • In simpler terms, think of the MSIN as the mobile equivalent of a username. It serves as a unique identifier that helps MNOs recognize and manage users.
2. Key Functions and Significance:
   • Service Registration: When users register for various services (such as multimedia services), the MSIN identifies them.
   • Communication Identification: It comes into play when users send SMS messages or make calls.
   • Billing: MNOs can accurately charge users for the services they use based on their MSIN.
   • Security: The MSIN is crucial for authenticating and authorizing network access.
3. How MSIN Works:
   • MSIN authenticates and authorizes user access to the network. It ensures a smooth and secure mobile experience.
   • When users register for services, make calls, or send text messages, the MSIN identifies their SIM cards.
   • Accurate billing relies on the MSIN, allowing MNOs to charge users appropriately.
4. Difference Between MSIN and IMSI:
   • MSIN is part of the International Mobile Subscriber Identity (IMSI).
   • The last ten digits of the 15-digit IMSI constitute the MSIN.
   • While both identify mobile users, they serve different purposes:
     • IMSI: A 15-digit number that includes the Mobile Network Code (MNC), MSIN, and Mobile Country Code (MCC). It provides detailed information and is fundamental for overall user identification and network operations.
     • MSIN: Essential for identifying individual mobile subscribers and vital for personal identification.
5. MSIN vs. Mobile Phone Number:
   • Although the MSIN can be derived from the subscriber’s mobile phone number, it is not the same.
   • When subscribers change their phone number, they retain the same MSIN.
   • In summary:
     • MSIN: Who you are (subscriber)
     • Mobile phone number: What number you use
6. MSIN vs. ICCID:
   • ICCID (Integrated Circuit Card Identification) is an 18-22-digit number printed on the back of a SIM card.
   • ICCID identifies the physical card itself (or virtual SIM card for eSIMs) and remains unchanged even when switching devices.
   • MSIN, on the other hand, is assigned to each mobile subscriber via the SIM card and is unique to each user.
7. Caution:
   • Treat your MSIN with care—it’s a unique identifier associated with your subscription.
   • Avoid sharing it publicly to prevent unauthorized access or identity theft.