Short for Integrated Circuit Card Identifier, an ICCID number is a unique 19–20-character value that is found in every SIM card. The information an ICCID number holds ensures that your device connects to cellular networks across the globe and that your SIM card is traceable. The ICCID number is usually printed on the back of your SIM card. It can also be accessed through the Settings options on your smartphone.

The ICCID number takes the MM CCC IIII NN NNNN NNNN C format. Let’s break it down to understand it better.

• The first two digits are the Major Industry Identifiers (MII). They are used to distinguish the SIM card from other types of chip-based cards, like credit or ID cards. This value is “89” for the telecommunication sector.
• The next two or three digits denote the country code. This value, determined by the International Telecommunication Union (ITU), stands for the country the SIM card is associated with.
• The Issue Identifier (II) or Mobile Network Code (MNO) follows the country code. This one- to four-digit-long value indicates the network operator and is essential for the SIM card to connect to the home network.
• The next 10 digits are the SIM number or the account ID. These digits are unique to every SIM card and help in SIM-management tasks like activation, deactivation, and tracking.
• The last digit is known as the check digit or the checksum. It is calculated using the Luhn algorithm and validates the integrity of the ICCID.

Here are the different purposes of the ICCID number.

• SIM Card Identification: Network providers often check the ICCID to authenticate the SIM card. This information is used when activating a new SIM card or deactivating it.
• SIM Card Management: As ICCIDs are unique to each subscriber, network operators use them to keep track of SIM cards, access/manage account-related information, like the current prepaid plan, and troubleshoot SIM-card-related issues.
• Roaming: ICCIDs help subscribers connect to visited networks with minimal hassle, enabling seamless connectivity in a foreign country.
• Security: Network operators can also use ICCIDs to detect unauthorized SIM card activity. They achieve this by tracking the usage of the same ICCID on multiple devices in a short period