IMEI, IMEISV and MEID: Device Identifiers Compared
· TR Vertriebs GmbH
An overview of how the three central device identifiers differ in structure, length and purpose.
Anyone who checks, buys or repairs devices runs into several identifiers that look alike at first glance: IMEI, IMEISV and MEID. All three identify mobile hardware, but they come from different technical backgrounds and serve different purposes. Knowing the differences prevents mix-ups when recording devices in an inventory system and clarifies which number is suited to which task. This article sorts the three identifiers by structure, length and area of use, and shows where they overlap in everyday practice.
The IMEI (International Mobile Equipment Identity) consists of exactly 15 decimal digits. The first eight form the Type Allocation Code (TAC), which marks the manufacturer and model type. Six digits follow as a device-specific serial number, and the final digit is a Luhn check digit that makes simple typos detectable. The IMEI is stored in the device independently of any network and can be shown on almost any phone using the *#06# key sequence. It is the most common identifier for blocklist and provenance checks.
The IMEISV (IMEI Software Version) is 16 digits long. It takes the first 14 places of the IMEI, meaning the TAC and serial number, but drops the Luhn check digit. Instead it appends a two-digit Software Version Number (SVN) that broadly marks the state of the device firmware. Network operators use the IMEISV to recognise the software level of connected devices. For inventory and blocklist checks it matters less, because the 15-digit IMEI is the standard there.
The MEID (Mobile Equipment Identifier) comes from the CDMA world and usually consists of 14 hexadecimal characters, that is digits and the letters A to F. It replaced the older 32-bit ESN (Electronic Serial Number) once that number space grew scarce. Notably, the 14-place MEID matches the first 14 places of an IMEI in structure, which is why devices for CDMA and GSM networks often carry both identifiers. In many regions CDMA networks have since been shut down, so the MEID mainly appears on older devices.
In practice, *#06# shows one or more of these identifiers depending on the device. Dual-SIM devices have their own IMEI per radio module, so two 15-digit numbers appear. The numbers can be cross-checked against the packaging label, the device information in the operating system and sometimes the SIM tray engraving. If the on-screen display and the label do not match, that is a clear warning sign that justifies a closer inspection.
For buying and trading, the IMEI is the decisive number, because it lets you query the model assignment, blocklist status and activation locks. The IMEISV adds a hint about the firmware level but does not replace the IMEI. The MEID now plays a role almost only with old devices or imports from CDMA markets. Keeping the fields cleanly separated in an inventory system prevents a hexadecimal MEID from being recorded as an IMEI by mistake and then wrongly flagged as invalid by the Luhn check.
In short: the 15-digit IMEI is the universal device identifier for GSM and LTE/5G networks, the 16-digit IMEISV adds the software level, and the 14-digit MEID stems from CDMA technology. All three denote the hardware, not the SIM card or the subscription. Keeping these roles apart means recording stock correctly and reading check results the right way. When in doubt, generate the number directly on the device with *#06# and compare it against the paperwork.