What Is My Phone’s IMEI, And What Is It For? [MakeUseOf Explains]

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You might have heard the acronym “IMEI” and know it relates loosely to the identity of your phone, but do you know exactly what it’s function is and what it is used for? Every new phone sold should have a unique IMEI number that is meant to remain the same for the lifetime of that product.

As smartphones increasingly become the target of theft across the world, the value of an IMEI number – and more importantly having a record of your device’s number – is not to be underestimated. In this article we’ll explore why our mobile devices need an IMEI and run through the basic methods that will enable you to find and record yours.

What Is An IMEI

IMEI literally stands for International Mobile Equipment Identity. The clue’s in the name, but each and every device should have a unique IMEI to differentiate it from the rest of the pack. When you buy a new phone you may notice the IMEI on the box or even the receipt. If ever you have to take your phone in for repair then there’s a good chance the IMEI will be noted for warranty and identity purposes.

A standard IMEI number is a 14 digit decimal string accompanied by an additional check number and an IMEI/SV (with the SV standing for software version) is 16 decimal digits, though these only usually appear on newer devices. The purpose of an IMEI goes beyond simple identification and the number can be used to block devices from accessing the cellular network. If your phone is stolen and you notify your service provider, they will block the device from their network and in some regions other networks too. Police often keep a record of stolen phones and use IMEI numbers as identification.

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As of 2004, the current format for these unique identifiers is AA-BBBBBB-CCCCCC-D. The first two portions labelled A and B are known as the type allocation code (TAC), and these directly relate to the manufacturer and model of the phone. As an example, the current iPhone 5 has a TAC of 01-332700 and the Samsung Galaxy S2 uses 35-853704. The section of the code labeled C is a serial number unique to the handset and defined by the manufacturer. The last digit is a checksum, used for verifying the entire string.

The IMEI is locked to the device, and has no relation to the SIM card. If your phone is stolen, settings reset and the SIM card is replaced, the IMEI will not change without further intervention. If your phone is stolen and you attempt to block it using the IMEI, be sure to ask your carrier if this block will extend to other networks as well. If not, you might want to try contacting the other major networks in your region to ask what can be done. In certain regions changing the IMEI number is illegal without a good reason to do so, and the practice is generally frowned upon as there are very few valid reasons for doing so.

While it may be illegal to change the IMEI of a device, it does happen. Thieves in particular will attempt to take non-blacklisted numbers and apply them to their stolen devices in order to make them usable again. For this reason it comes highly recommended that you never share or post your IMEI online, else you may find that your device can be cloned. In the interests of ongoing investigations by authorities, an IMEI can be used when wiretapping a device as well.

How To Find Your IMEI

The majority of mobile devices will display their IMEI by entering *#06# on the keypad. This is generally enough to reveal the code on older devices and most newer ones too, though you can also use other techniques if you’ve got a phone manufactured by one of the following:

  • iOS (iPhone, LTE/3G iPad): Found in the Settings > General > About menu.
  • Android: Found in the “Settings” menu under “About Phone”.
  • Older Sony or Sony Ericsson: Enter “* Right * Left Left * Left *” on the keypad.
  • Blackberry or newer Sony Ericsson: Found in the “Options” menu under “Status”.

If you would like to check exactly what your phone’s IMEI number says about your handset then you can do so using IMEI.info.


The IMEI numbers in your mobile devices are important and unique identifiers that you should make a note of right now if you haven’t already. If your phone is stolen then the IMEI won’t help get it back, though you will be able to take some solace in the knowledge that you can render the device useless as a phone.

Have you ever blocked a phone using its IMEI? Have you got a record of the identification numbers stored in your device? Add your thoughts and questions in the comments, below.

Image Credit: Intro Image (Shutterstock)SIM Card (kalleboo), Android Phone (Johan Larsson), Mobile Phone Recycling (meanestindian), Warning Sign (Andwar)

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20 Comments - Write a Comment


Knut H. Flottorp

IMEI is the identification of the phone itself, while the number – MSIDN (Mobile Subscriber ID Number) is on the SIM as you say, and what is used to dial to you.

You operator has an equipment register: The IMEI register that is consulted every time someone initiates a request for resources – like place a call or send a message. The HLR (Home Location Register) and VLR (Visitor LR) are the main parts of the mobile network centre switch. A phone that is stolen should be blacklisted in the IMEI immediately, and propagated to all other GSM operators. However, some people came up with the notion of using the IMEI to “lock” the phone to a specific operator for a time – 2 years, and enable this to barr usage by others operators. So they drop the trace of stolen handsets. Beware of this should those that steal your handset also use your phone and you are charged for this usage. According to the GSM standard, as long as you have reported your phone – your phone number (MSIDN) is enough – they should have stopped that call from being placed, and you are not liable for the cost that they incurred for faulty installation.

With a good management system, the operator should be able to locate your phone within 100 feet from where it last was on, so before wiping out a phone that you dropped in your office, your operator should be able to tell you that “it is in your office and you did not drop it on the way home, and it has been in the same place now for 3 hours, so should be the same place tomorrow morning.”

Cody Richards

Please remember that most mobile operators will not attempt to locate a phone without intervention from emergency services. Carrier location is mainly for E911 services. Any location service that your carrier provides is just value add.

Robert Wm Ruedisueli

You can install “phone home” software on many phones, that allows you to retrieve the phone.

I wish they also made “blanking” software that removes all your passwords and data from the phone as well.

Knut H. Flottorp

Wrong Cody.
The operators have systems that manage the networks – “OSS”. Should you have a dropped call, it will show up as a network fault and with repeated failures the operator will “do something” like install a ‘repeater” to improve the coverage.

That the operator does so little is their problem. Operators such as Vodafone and AT&T may seem impossible to confront and they will try to bill you for those calls. But send that invoice on to the FCC or Ofcom for review. There are so many stupid, incompetent consultants that have been hired.

Knut H. Flottorp

On all GSM phones the used (“subscriber”) and the keys and data including encryption that identifies this is contained on the SIM – Subscriber Identity Module.

The phone itself is identified by the “Equipment code” – IMEI and is a structured serial number that is discussed here. It is like the chassis number combined with the motor number of your car and found in the registration documents and used by the police to trace stolen cars – that you find in the Vehicle registration documents.

The CDMA phones does not have this.

Smartphones have apps that retrieves these numbers and I have software installed that will wipe out all my files, passwords and settings, erase the OS and make the phone useless. I have used a variant that used face recognition that worked fine, but this has been replaced by software more generally available and demanded by those that send me confidential information. But the IMEI is unchanged, so should they install new OS, and replace the SIM, the operator will have it “blacklisted” and could call the police to collect it. They will not do that for one phone, but activate 1000 phones at the same location, and await for the Men in Black.

Lisa Santika Onggrid

Very informative. So if our phone goes missing we could ask our carrier for locating it if we have the IMEI number? Should’ve known this before.

Knut H. Flottorp

We have murder investigations where the phone and the phones of various suspects are traced weeks after, and submitted in court as evidence.



how to find EMEI on windows phone :
call -> dial -> *#06#
(it works on the most phones not even smartphones (old nokia and sony ericsson))

Also :
settings -> about -> more info

Alba Spam

thank you


Usman Mubashir

older phones have imei stored in


phones with more than one sim facility have more than one imei



You say “it comes highly recommended that you never share or post your IMEI online”, then point people to imei.info, where they’re prompted to… enter their IMEI online. Brilliant.

Knut H. Flottorp

You can share your IMEI with everybody, it is utter worthless.

The registration number of a CDMA phone is something else, that someone from the FCC should explain to you. It is only used in the US. The SIM-card with the MSIDN (“phone number”) and IMEI is a GSM standard.

The IMEI is NOT consulted except initially, to configure your phone for VAS such as multi-media messaging, this is stored on the SIM the first time the phone connects to the network, allowing this to be changed as you move around in other countries. The purpose of the IMEI is to block a stolen phone, and identify phones on contract.


Robert Wm Ruedisueli

More interestingly to give you an idea of how deeply embeded the IMEI is, on many phones you can reflash flash everything on the entire phone to stock, and replace or wipe the SIM card, and it will still not wipe the IMEI, because it is encoded onto the ROM sectors on the CPU which are usually exceedingly hard to flash or otherwise alter.

Knut H. Flottorp

It is IMPOSSIBLE to change according to the GSM specifications.
But as said above, there are some that have not read this.
Beware that the most likely response should you manage to change the IMEI is that the phone will be rendered useless – “Bricked”.


Lisa Santika Onggrid

I set my Monte to send a message to my other number in case it’s stolen and the thief tries to insert new SIM card. The message includes the phone’s IMEI.


vineed gangadharan

so we can track people if we have their imei???


Ole Funch

Thx – good article ?


Keith D.

Wow! I never knew! But… shouldn’t I now feel… you know, ENLIGHTENED?! lol



nice article very well written …. some thing i can …makeuseof ….. really no kidding


Anand Kumar

You can decode IMEI to identify Manufacturer, Brand, Model, some technical
capabilities and valid devices. And carrier use IMEI to identify in case your phone lost – stolen and blacklist this device.

Have many website to check your IMEI number to get details about your phone like manufacturer date, factory, purchase country, purchase date and blacklist information like imeidata.net. I hope that help.

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