# IMEI

> A unique 15-digit number that identifies your handset to mobile networks; used to check carrier locks, register devices and block stolen phones.

Source: https://viasimo.com/glossary/imei/
Also known as: International Mobile Equipment Identity, IMEI number

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An IMEI (International Mobile Equipment Identity) is a unique 15-digit number that identifies your handset to mobile networks. It belongs to the device itself, not to any SIM or phone number, and dual SIM phones have two of them: one for each modem slot.

The quickest way to find yours is dialling *#06#, which works on virtually every phone; it is also listed in Settings, printed on the original box and often engraved on the SIM tray. Networks use the IMEI to recognise the hardware connecting to them, to block handsets reported stolen and, in some countries, to enforce device registration rules.

Travellers meet the IMEI in three situations. The first is checking whether a phone is unlocked and eSIM capable before buying a plan; carriers and manufacturers can look both up from the IMEI, and a [carrier lock](/glossary/carrier-lock/) is the most common reason an otherwise compatible phone rejects a travel eSIM. The second is [SIM registration](/glossary/sim-registration/) rules: countries such as [Turkey](/destinations/turkey/) require foreign phones to be registered by IMEI for long stays, after which unregistered devices are blocked from local SIMs; short visits on a travel eSIM are generally unaffected. The third is theft, since reporting the IMEI lets networks blacklist the handset so it cannot be reused.

The common confusion is mixing up the identifiers. The IMEI names the phone; the ICCID names the SIM or eSIM profile; your phone number belongs to the plan. Swapping SIMs, or installing ten different eSIMs, changes nothing about the IMEI.

A concrete example: before a trip, you dial *#06#, note the IMEI and use your carrier's website to confirm the phone is unlocked. You then verify the model against [device compatibility](/device-compatibility/) and install your eSIM with confidence. If an eSIM refuses to activate anyway, the [troubleshooting guide](/magazine/esim-not-working-troubleshooting-guide/) starts from exactly these checks, and the [iPhone eSIM guide](/magazine/esim-for-iphone-complete-guide/) shows where Apple lists each number.