What is an IMEI number?
The IMEI is the 15 digit identity of your phone itself. Here is how to find it, what networks use it for, and why a dual SIM phone has two.
An IMEI (International Mobile Equipment Identity) is the 15 digit number that identifies your phone as a piece of hardware. Not your SIM, not your number, not your account: the handset.
What networks use it for
Every time a phone connects to a mobile network it reports its IMEI. Networks use it for two things that matter to you.
Blocking stolen phones. Operators in many countries share blocklists of IMEIs reported stolen. A blocked handset is refused by every network in that list, whatever SIM is in it. This is why the IMEI is the first thing an insurer or the police asks for, and why it is worth writing down somewhere that is not the phone.
Knowing what the device can do. The first eight digits say which model it is, so the network knows whether to offer it 5G, VoLTE or a particular band before it has negotiated anything.
How to find it
Dial *#06# in the phone app. The panel that appears shows the IMEI immediately, and on an eSIM phone it shows the EID too.
It is also in Settings, General, About on iPhone, and Settings, About phone on Android. On an iPhone it is laser etched into the SIM tray on older models, and printed on the original box.
Why dual SIM phones show two
An IMEI identifies a radio connection to a network, not strictly the body of the phone. A phone that can hold two active lines has two, labelled IMEI1 and IMEI2, one per SIM slot or eSIM profile.
This is normal and not a sign of anything wrong. When support asks for "the IMEI" and you have two, give the one belonging to the line that is not working, or give both.
What it is not
The IMEI is not a password and not a secret, but it is not harmless to publish either. It is the number used to check whether a phone is blocklisted or under warranty, and there are services that will tell a stranger things about your device from it. Share it with your operator, your insurer or a repair shop, and not in a public post.
Changing an IMEI is illegal in most countries, including across the European Union and the United Kingdom, precisely because it would defeat the stolen phone blocklists.
Quick answers
Is the IMEI tied to my SIM or my phone?
The phone. Move your SIM to another handset and the IMEI reported to the network changes, because it belongs to the device.
Why does my phone show IMEI1 and IMEI2?
Because it supports two lines at once. Each one has its own identity on the network. Nothing is wrong.
Does installing an eSIM change my IMEI?
No. The IMEI is fixed in the hardware. Installing, deleting or switching eSIM profiles does not touch it.
Can I check whether a used phone is blocklisted?
Yes, and you should before buying one. Ask the seller to dial *#06#, then check the number through your national operator or the checking service your country provides. A phone that is blocked in one country is often blocked in others too.