ICCID explained

An ICCID (Integrated Circuit Card Identifier) is a globally unique classifier that can be used to identify SIM hardware (most prominently physical SIM cards). This 19 to 20 character-long number is stored digitally, but typically also physically engraved into the SIM card's body. The ICCID may sound similar to an IMEI, but both are used to identify entirely different components. Physical eSIMs have an eUICCID, which is a different classifier; however, they are typically also assigned an ICCID.

What is an ICCID number?

While everyone knows what a SIM card is, ICCID is a term you may not have heard before, even though every SIM card has one. The ICCID is a unique number that can be used to tell apart from one SIM card from another. Every SIM Card worldwide has a unique ICCID (Integrated Circuit Card Identifier). Nowadays, even eSIM profiles and virtual SIM cards have a unique ICCID. ICCIDs are digitally stored in SIM Cards, and, in case of physical SIM cards, are also printed on the SIM card body.

The composition of an ICCID number

An ICCID typically consists of 19 to 20 characters. Some SIM cards do not have the complete ICCID number engraved on its body; in some cases, only the last 13 digits will be visible. An ICCID number is formatted as follows:

MMCC-IINN-NNNN-NNNN-NN C(X)

An ICCID typically consists of 19 to 20 characters. Some SIM cards do not have the complete ICCID number engraved on its body; in some cases, only the last 13 digits will be visible. An ICCID number is formatted as follows:

  • MM is a constant:For IoT SIM Cards, these first two digits are always 89. This code clearly distinguishes SIM cards from any other type of chip card, such as a credit card.
  • CC is the country's code: These codes are assigned by the ITU (International Telephony Union) and differ from MCCs (Mobile Country Codes), which are used in IMSIs (International Mobile Subscriber Identities)
  • II is the Issue Identifier: This number identifies the mobile network that issued your SIM card. This is particularly important when a device roams in another country. Nowadays, many partnerships between cellular service providers exist, so you II number may be the one from a partner company, rather than the one company you actually bought the SIM from.
  • N is the Account ID: This ID is what truly distinguishes your SIM card from any other SIM card on the world.
  • C is a sum: This sum is calculated from all previous digits by applying the Luhn algorithm.
  • X is an additional digit:  This digit is derived from a command known as 'AT!ICCID?', however officially, this number is not considered part of the ICCID.

The first two digits of an IoT SIM Card ICCID are always 89, a code that identifies the telecommunications industry. This code distinguishes the SIM from other types of chip cards, including credit cards and some types of government or business identification.

What is the difference between an ICCID, IMSI, and IMEI?

The ICCID was conceived to identify all SIM hardware. However, there are other identifiers that are used for mobile network equipment. The most prominent ones are IMSI and IMEI:

IMSI

The IMSI (International Mobile Subscriber Identity) number is what cellular networks used to identify a specific subscription that is included as part of your data plan. Every time a device wants to establish a connection to the network, the network will identify the device by the IMSI. While this may sound similar to ICCID, both of these identifiers were conceived to identify different entities. The ICCID is used to identify the SIM Hardware, while the IMSI is used to identify the type of connectivity service.

IMEI

The IMEI (International Mobile Equipment Identity) number is typically printed on the batter component of any device with networking capabilities. It is a unique identifier for each device and is checked against a worldwide IMEI database when connected.

eSIMs and eUICCIDs

With the emergence of eSIMs (embedded subscriber identity module) a new identification number, known as the eUICCID number, has been established. A company may want to manufacture physical eSIMs but also generate and sell eSIM profiles. In some cases, these carriers will collaborate with other providers in order to create eSIM profiles, which means multiple parties may be involved in the creation of an eSIM. To simplify this situation and avoid confusion, the networking industry has created the eUICCID to identify physical eSIMs separately. The eUICCID number is an entirely different and unique classifier, however, an ICCID is typically still created along with the eSIM profile.

  • ICCID is a unique identifier that can be used to distinguish each SIM hardware on the planet.
  • This number contains 19 to 20 characters and is engraved both digitally and physically onto the SIM Card.
  • For IoT Sim Cards the first digits of the ICCID are always 8 and 9.
  • eSIMs typically have an ICCID but are also assigned another classifier known as eUICCID.