International Mobile Equipment Identity

Devices without a SIM card slot or eSIM capability usually do not have an IMEI, except for certain early Sprint LTE devices such as the Samsung Galaxy Nexus and S III which emulated a SIM-free CDMA activation experience and lacked roaming capabilities in 3GPP-only countries.

Instead, mobile operators are encouraged to take measures such as immediate suspension of service and replacement of SIM cards in case of loss or theft.

The linkage between regulatory approval and IMEI allocation was removed in April 2000, with the introduction of the European R&TTE Directive.

When someone has their mobile equipment stolen or lost, they can ask their service provider to block the phone from their network, and the operator may do so, especially if required by law.

If the local operator maintains an Equipment Identity Register (EIR), it adds the device IMEI to it.

[11] In Australia the Electronic Information Exchange (EIE) Administration Node provides a blocked IMEI lookup service for Australian customers.

The service allows up to three lookups per day[14] and checks against a database that is updated daily by the three major mobile network operators.

In 2012, major network companies in the United States, under government pressure, committed to introducing a blocklisting service, but it's not clear whether it will interoperate with the CEIR.

The CTIA refers users to websites at www.stolenphonechecker.org[19] and the GSMA[19] where consumers can check whether a smartphone has been reported as lost or stolen to its member carriers.

[19] It is unclear whether local barring of IMEI has any positive effect, as it may result in international smuggling of stolen phones.

[citation needed] Law enforcement and intelligence services can use an IMEI number as input for tracking devices that are able to locate a cell phone with an accuracy of a few meters.

[21] An IMEI number retrieved from the remnants of a Nokia 5110 was used to trace and identify the perpetrators behind the 2002 Bali bombings.

[28] Other countries that have adopted some form of mandatory IMEI registration include India, Pakistan, Indonesia, Cambodia, Thailand, Iran, Nigeria, Ecuador, Ukraine, Lebanon,[29] and Kenya.

This has the problem that imported phones and some non-imported phones such as older OnePlus models or select CDMA-capable LTE devices (including models sold on Verizon or Sprint) will not work for voice calls even if they have the LTE/5G bands for AT&T and Telus and support VoLTE on competitors or via VoLTE roaming.

The CDMA Mobile Equipment Identifier uses the same basic format as the IMEI but gives more flexibility in allocation sizes and usage.

The purpose of the Check Digit is to help guard against the possibility of incorrect entries to the CEIR and EIR equipment.

Logistics (using bar-code reader) and EIR/CEIR administration cannot use the Check Digit unless it is printed outside of the packaging, and on the ME IMEI/Type Accreditation label.