How to check an IMEI number, and what the check can and cannot prove
The short answer. 15 digits: 8 for the model (the TAC), 6 for the handset's serial number and 1 check digit worked out from the other 14 with the Luhn formula. A correct check digit proves only that the number was copied without a typo. Whether a phone is stolen or blocked is in India's CEIR register, checked through Sanchar Saathi.
Dial *#06# on the phone and it shows its IMEI; a dual-SIM phone shows two. The number is also on the box, the purchase invoice and, on many phones, the SIM tray. Paste it into the IMEI Checker to check the last digit and see each part. The check runs in your browser and the number is not sent anywhere.
A worked example
Every example on this page uses the IMEI Checker's own example number, 49-015420-323751-8, the one its Try an example button fills in. Do not post a real phone's IMEI in a forum or a bug report.
| Part | Digits | What it is |
|---|---|---|
| Reporting body | 49 | BZT / BAPT / Reg TP, Germany, a body no longer issuing new codes |
| TAC (model) | 49015420 | the Type Allocation Code; the open Osmocom list names it as a Nokia 3110 |
| Serial | 323751 | the handset's own number within that model |
| Check digit | 8 | worked out from the 14 digits before it |
The check digit, worked by hand
Take the first 14 digits, 49015420323751. Starting from the rightmost and moving left, double every second digit, beginning with the last one. A doubled result above 9 has 9 taken off (14 becomes 5, 18 becomes 9).
| Digit | 4 | 9 | 0 | 1 | 5 | 4 | 2 | 0 | 3 | 2 | 3 | 7 | 5 | 1 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | yes | yes | yes | yes | yes | yes | yes | |||||||
| Value | 4 | 9 | 0 | 2 | 5 | 8 | 2 | 0 | 3 | 4 | 3 | 5 | 5 | 2 |
The values add up to 52. The check digit is what brings the total to the next multiple of ten: 60 − 52 = 8. The number ends in 8, so the IMEI Checker says Check digit correct.
What the check catches:
| You type | The checker says |
|---|---|
| 490154203237519 (last digit wrong) | The last digit is 9, but the first 14 digits call for 8 |
| 490154203273518 (two digits swapped, 37 → 73) | The last digit is 8, but the first 14 digits call for 3 |
| 49015420323751 (14 digits) | The check digit was left off; the full IMEI is 490154203237518 |
| 4901542032375186 (16 digits) | An IMEISV: the same 14 digits and software version 86, no check digit |
What the check cannot prove
One of the ten possible last digits always fits, so a made-up 15-digit number passes about one time in ten. A correct check digit therefore does not prove:
- that the phone is not stolen or blocked. That record is held by operators and, in India, by the Department of Telecommunications' CEIR register. Query it on Sanchar Saathi's Know Your Mobile (KYM) page, or send
KYMfollowed by the 15-digit IMEI by SMS to 14422. - that the phone is genuine. A cloned or altered phone can show a well-formed IMEI copied from another handset. An IMEI whose first 14 digits are all the same is a placeholder; the checker flags it as one that has been wiped or changed.
- the exact model. The brand and model come from the Osmocom TAC list, about 22,000 codes under CC BY-SA 3.0, which covers mostly older handsets. When a TAC is not in it, the page says so rather than guess. The full register is the GSMA's licensed IMEI database, not used here.
- warranty, the manufacturer's serial number or a carrier lock. None of these is in the IMEI; they sit in the manufacturer's and the operator's own records.
If your phone is lost or stolen, report it through CEIR at ceir.sancharsaathi.gov.in so the IMEI is blocked on Indian networks.
Checking a list
The Check IMEI Number Validity page opens on the list view: paste up to 2,000 IMEIs, one per line, and each row is marked Correct, Should end followed by the right digit, Check digit added, or Not an IMEI. Copy as table pastes the results into a spreadsheet.
Questions people ask
How do I check if an IMEI number is valid?
Dial *#06# to show the 15-digit IMEI, then paste it into the IMEI Checker. It works out the check digit from the first 14 digits with the Luhn formula and compares it with the last one. For 49-015420-323751-8 the first 14 digits call for 8, so the number is well formed. That is all the check proves.
Can an IMEI check tell me if a phone is stolen?
No. Stolen and blocked status is held by mobile operators and, in India, by the government's CEIR register, not in the number itself. Check it on Sanchar Saathi's Know Your Mobile page, or send KYM followed by the 15-digit IMEI by SMS to 14422. A correct check digit only shows the number was copied correctly.
What do the 15 digits of an IMEI mean?
The first 8 are the Type Allocation Code, which identifies the model; its first 2 name the body that issued it, such as 35 for TÜV SÜD BABT in the UK or 86 for TAF in China. The next 6 are the handset's serial number. The last digit is a Luhn check digit worked out from the other 14.
Does a valid IMEI mean the phone is genuine?
No. About one in ten made-up 15-digit numbers has a correct check digit, and a cloned phone can show an IMEI copied from a real one. The check catches typing mistakes, not fakes. Buying second-hand in India, check the number on Sanchar Saathi's Know Your Mobile service before you pay.
Why does the IMEI checker not show my phone's model?
The model comes from the open Osmocom TAC list, about 22,000 codes kept by volunteers, which covers mostly older handsets. Many recent phones are not in it, and then the page says so instead of guessing. The complete register is the GSMA's licensed IMEI database, which this free tool does not use.
Sources
Checked 15 Oct 2026:
- GSMA: TS.06 IMEI Allocation and Approval Process, version 27.0 (the TAC, serial and check digit, and the reporting body codes in Annex A)
- Department of Telecommunications: Sanchar Saathi, its Know Your Mobile service (also by SMS "KYM" and the IMEI to 14422) and CEIR for blocking a lost or stolen handset
- Osmocom: the TAC database, CC BY-SA 3.0 (TAC 49015420 is listed as Nokia 3110)
- Every verdict on this page is the IMEI Checker's own output, from its check function, for the numbers shown. The one-in-ten figure follows from the check digit: exactly one of the ten possible last digits fits.