The Integrated Circuit Card ID (ICCID) is a globally unique serial number which is 19 or 20 digits in length. This number is present on every Subscriber Identity Module (SIM) card to identify it, so no two ICCIDs are alike. 

Anybody working with cellular networks or Internet of Things (IoT) devices must understand how ICCIDs work and how they compare with other mobile networking identification numbers like International Mobile Subscriber Identity (​​IMSI) and International Mobile Equipment Identity (IMEI). 

What role does the ICCID play in cellular networking? 

Whenever you want to connect your personal device with a mobile network provider, you must use an ICCID. For example, a customer looking to activate a new line of service or get in contact with support teams will contact a Mobile Network Operator (MNO). The MNO will respond by reading the ICCID and subsequently connecting the subscriber to the correct network. 

ICCIDs are also essential for companies deploying cellular IoT devices, as the identifiers ensure only authorized devices connect with the cellular network. 

You can find the ICCID of your device on the SIM card itself, the packaging the card came in, or through the device. Smartphones often have the numeric under settings, for instance. 

What do the digits in an ICCID number mean? 

We can break down the structure of an ICCID to examine how its individual components work together. 

• The first two digits are always 89, which shows that the SIM card operates within the telecommunications industry. Other chips, like those in credit cards or business identification cards, may use different digits. 
• The next two or three digits are the country code, which the International Telephony Union (ITU) assigns to each region of the world. 
• The next one to four digits are the mobile network code (MNC) of the mobile network which issued your SIM. If your device ever roams into another region, the MNC will connect your device back to its home network or find another cellular network that partners with your service provider. 
• The following digits are unique and help distinguish your SIM card from others in the same region or network. 
• The final number is a check digit which confirms whether the ICCID is valid. 

While ICCIDs are unique, one SIM card may have multiple ICCIDs. For example, a device roaming internationally must work with multiple networks in different regions. Multi-ICCID support enables it to switch to a new network seamlessly. 

How does ICCID compare with other mobile network identifiers? 

The ICCID does not operate alone. Some forms of mobile equipment use the Mobile Station ISDN Number (MSISDN), essentially a phone number with a country code for routing voice calls and text messages. Others deploy encryption using the ​​​​Ki (Authentication Key) and ADM (Administrative Management Key) cryptographic codes for authentication purposes, such as authorizing a user to apply administrative actions. 

Cellular network identifiers more in line with what ICCID aims to achieve are IMEI and IMSI. 

The International Mobile Equipment Identity (IMEI) 

Often found on the battery component of a device, the International Mobile Equipment Identity identifies a device within a network. A global database is available for IMEI reference. 

IMEI and ICCID share a similar function. But while IMEI identifies a mobile device, ICCID identifies the SIM card. 

International Mobile Subscriber Identity (IMSI) 

If you have a data plan active on your mobile device, the International Mobile Subscriber Identity connects your line of service to a specific data plan so your cellular network may establish the connection. 

IMSI and ICCID play similar roles in cellular networking. But ICCID refers to the SIM card, while IMSI connects the subscriber to the cellular service. 

How has ICCID adapted to embedded SIM technology? 

As SIM card technology has progressed, the ICCID system has undergone a few changes which may confuse some of its early adopters. 

What is embedded SIM (eSIM)? 

The development of embedded SIM marks a turning point in mobile networking. As its name suggests, this type of SIM card solders onto the device’s motherboard, embedding itself into the device. 

eSIMs have significant advantages over traditional physical SIM cards. One eSIM can switch between multiple SIM profiles and work with multiple network subscriptions simultaneously. However, this benefit also comes with complications regarding ICCIDs, hence the introduction of eUICCID. 

What is eUICC? 

The embedded Universal Circuit Card (eUICC) is the software allowing eSIMs to provision SIM profiles remotely. Cellular network providers can add, remove, or manage these profiles without requiring the user to physically swap out SIM cards. eUICC can work with traditional SIM cards in some instances. 

With the introduction of eUICC, a new type of identification became necessary. 

What is eUICCID? 

The proliferation of eSIM came with a parallel development in eUICCIDs, a new type of cellular network identification number. 

Thanks to the flexibility of eSIM technology, it’s possible the eSIM manufacturer and the provider of the SIM profile are different companies. Sometimes, multiple parties may contribute to the provisioning of cellular service and SIM profiles. 

The industry collectively simplified this situation with eUICCID, a separate ID from ICCID identifying the physical eSIM device. 

What are the benefits of ICCID? 

ICCID provides numerous advantages for both mobile carriers and subscribers: 

• Enhanced Security: ICCID, along with other SIM card data, helps authenticate a user's identity, making mobile communications more secure. 
• Streamlined Subscriber Management: Mobile carriers can easily track and manage subscribers using ICCID numbers, ensuring smooth connectivity and service provisioning. 
• Simplified Device Switching: With an ICCID, users can transfer their mobile numbers and services to new devices by simply switching their SIM cards. 
• Fraud Prevention: ICCID helps detect and prevent fraudulent activities by identifying unauthorized or cloned SIM cards. 

How does Sinch work with ICCID? 

At Sinch, we harness the power of ICCID to provide seamless and secure mobile communication solutions. Our products and services, such as SMS API and Number Portability, leverage ICCID data to ensure accurate message routing, efficient number porting, and enhanced customer experience. By incorporating ICCID into our offerings, we uphold our commitment to delivering top-notch mobile connectivity solutions to businesses and consumers alike.