What is the SIM card? And what is the SIM number?

A SIM (Subscriber Identity Module) card is an integrated circuit card that stores the ICCID (Integrated Circuit Card Identifier) number, the IMSI (International Mobile Subscriber Identity) number, and other information about the wireless carrier.

Every SIM also prints a SIM number on the back of the SIM card to uniquely identifies this physical card. So the SIM number is the serial number of each SIM card.

As of today, wireless carriers are using 3 different formats to construct their SIM numbers:

1. ICCID Format - 89-CCC-II-AIN-checksum, where 89 is the MII (Major Industry Identifier) representing "Telecommunications administrations and Private operating agencies". CCC is the international Country Calling Code, II is the carrier's Issuer Identifier, and AIN is the Account Identification Number.

For example, 89-91-10-120000320451-4 is a SIM number in ICCID format. 89 is the MII required for all SIM numbers. 91 is the CCC representing India. 10 is the II representing Airtel as the carrier. 120000320451 is the AIN representing the SIM card owner's account. 4 is the checksum to ensure the integrity of the entire SIM number.

See "What Is the ICCID Number on My Phone" for more details on ICCID numbers.

2. IMSI Format - 89-MCC-MNC-MSIN-checksum, where MCC is the Mobile Country Code, MNC is the Mobile Network Code, and MSIN is the Mobile Subscriber Identification Number.

For example, 89-302-720-40000001234-9 is a SIM number in IMSI format. 89 is the MII required for all SIM numbers. 302 is the MCC representing Canada. 720 is the MNC representing Rogers as the carrier. 40000001234 is the MSIN representing the SIM card owner's account. 9 is the checksum to ensure the integrity of the entire SIM number.

See "What Is the IMSI Number on My Phone" for more details on MCC and MNC numbers.

3. Hybrid Format - 89-CCC-MNC-SN-Checksum, where CCC is the international Country Calling Code, MNC is the Mobile Network Code, and SN is a Serial Number that is mapped to an account in carrier's system.

For example, 89-01-410-301234567890-4 is a SIM number in Hybrid format. 89 is the MII required for all SIM numbers. 01 is the CCC representing United States. 410 is the MNC representing AT&T as the carrier. 301234567890 is the representing re the SIM card owner's account. 4 is the checksum to ensure the integrity of the entire SIM number.

SIM cards have 3 different sizes: SIM, microSIM and nanoSIM as shown below:

If the SIM card is inserted into your phone, you can find the SIM card number on the settings screen. But it may be displayed as the ICCID number in some phones like iPhone.

However, the IMSI number is not printed on the SIM card, or displayed on the phone's settings screen. You need special devices to read the IMSI number from your SIM card.

To decode a SIM card Number, use "ICCID/SIM Card Number Checker/Decoder" tool.

To generate some SIM card Numbers for testing, use "SIM Card Number Generator" tool.

⇒ ICCID/SIM Card Number Checker/Decoder

⇐ What Is the ICCID Number on My Phone

⇑ SIM (Subscriber Identity Module) Card

⇑⇑ Cell Phone FAQ (Frequently Asked Questions)