IMEI check

Enter an IMEI and we will check whether the number is well-formed and show which maker and model it was issued to. It is the first thing to do before buying a used phone: if the model behind the IMEI is not what the seller offers, you can stop right there.

The check runs in your browser. We do not store the IMEI or send it to a server: the browser downloads only a slice of the reference database by the first four digits, which thousands of models share.

What an IMEI is and how it is built

IMEI (International Mobile Equipment Identity) is a 15-digit number given to every phone, cellular tablet, modem and LTE smartwatch. Carriers use it to recognise a specific handset, and makers and repair shops use it for warranty and service records. A dual-SIM phone has two IMEIs; an eSIM has no IMEI of its own and uses the second slot’s number.

The first 8 digits are the TAC (Type Allocation Code). It is issued by a body authorised by the GSMA and is the same for every unit of one model variant, which is why the TAC tells you the maker and model. The next 6 digits are the serial number within that TAC. The last, fifteenth digit is a check digit calculated from the first 14 with the Luhn algorithm, the same one used for bank card numbers.

Some phones show an IMEISV with 16 digits. It is the same first 14 IMEI digits plus two digits of the modem software version, without a check digit. We accept it too: the model is decoded, the Luhn check simply does not apply.

What the check shows and what it does not

The Luhn check catches typos and made-up numbers: change one digit or swap two neighbours and the check digit no longer matches. We show what it should be so the mistake is easy to find. An IMEI of zeros or one repeated digit is what a phone shows after its modem firmware fails, which is a warning sign too.

From the TAC we look up the maker, model, model number and release year in an open reference database. If the model behind the IMEI differs from the one in the phone settings or on the box, the housing, board or box came from another device. If the TAC is not in the database, that is not proof of a fake: open databases are incomplete, especially for the newest models and small brands.

What the check does not do: it cannot tell whether a phone is reported stolen, blocked by a carrier, locked to someone else’s account or under warranty. That data is not public. Makers’ websites check warranty and authenticity, and links appear under the result. In the US and Australia, carrier associations run free blocked-phone lookups, also linked below.

Checklist for buying a used phone

1. Match the IMEI in three places: the *#06# screen, the settings and the box. All numbers must agree, and the model behind the IMEI must be the one you are buying.
2. Ask the seller to sign out in front of you. On an iPhone, Settings → your name → Find My must show Find My iPhone off, otherwise Activation Lock stays on. On Android, remove the Google account in settings, otherwise the phone asks for the previous owner’s password after a reset.
3. Check which market the phone was made for. The model number under Settings → General → About ends with a region code such as LL/A for the US. It affects warranty, bands and what comes in the box.
4. Test the screen for dead pixels and backlight bleed with our screen test, and swipe a finger across every corner of the touch layer.
5. Test the microphone and cameras: the microphone test and camera test open right in the phone’s browser. Play music at full volume to hear whether the speaker rattles.
6. Look at battery health: on an iPhone, Settings → Battery → Battery Health; on Android, the maker’s app or service menu. Below 80% the battery will need replacing soon.

More tests

Frequently asked questions