IMEI Validator

IMEI: the cellular handset fingerprint defined by 3GPP

The IMEI (International Mobile Equipment Identity) is a 15-digit numeric code that uniquely identifies every GSM, UMTS, LTE and 5G handset in the world. Standardized by 3GPP TS 23.003 and administered globally by the GSMA through the TAC Allocation system, the IMEI is what mobile carriers use to authenticate, whitelist or block a device on their networks — regardless of which SIM card is inserted.

To display the IMEI on virtually any phone, dial *#06# on the keypad. The number is also printed on the SIM tray, the original box and the regulatory label inside iOS Settings or Android About Phone. This validator runs entirely in your browser: nothing is transmitted to a server and no network query is made.

Anatomy of the 15 digits

The IMEI splits into three logical blocks:

• TAC (8 digits) — Type Allocation Code, granted by the GSMA to a manufacturer for a specific handset model and revision. Examples: 35-26-08-00 identifies an iPhone 12 Pro, 35-32-32-09 a Samsung Galaxy S6.
• Serial Number (6 digits) — sequential serial assigned by the manufacturer inside the TAC range.
• Check Digit (1 digit) — Luhn mod 10 checksum computed over the previous 14 digits.

A close cousin is the IMEISV (IMEI Software Version): also 16 characters, but the trailing digit is the SVN (Software Version Number, two digits) instead of a checksum. Networks query the IMEISV to detect firmware level for compatibility decisions.

The Luhn mod 10 algorithm applied to IMEI

Validation follows the same Luhn formula used by credit cards:

1. Starting from the right, double every digit in an even position (positions 2, 4, 6, ...).
2. If the doubled value exceeds 9, subtract 9 (equivalent to summing its digits).
3. Sum all 15 transformed digits.
4. The IMEI is valid when the total is a multiple of 10.

// 490154203237518
// even positions doubled: 9*2=18 -> 9, 1*2=2, 4*2=8, 0*2=0, 2*2=4, 7*2=14 -> 5, 1*2=2
// sum = 4+9+0+2+5+8+2+0+3+4+3+5+5+2+8 = 60  -> 60 % 10 = 0  -> valid

CEIR, blocklists and stolen-device tracking

The CEIR (Central Equipment Identity Register), operated by the GSMA, is the global blocklist of lost or stolen IMEIs. Once a carrier flags a device, partner operators worldwide can refuse service to that IMEI. In Brazil, Anatel maintains the SIIIM (Sistema Integrado de Inibicao de Modems e Aparelhos roubados), which integrates national carrier blocklists with the GSMA database. Anatel also requires every handset legally sold or imported to Brazil to have its IMEI homologated.

Beyond theft recovery, IMEIs power MDM (Mobile Device Management) enrollment in fleets — Microsoft Intune, Jamf, VMware Workspace ONE and Google Endpoint all key off IMEI when provisioning corporate devices. Law enforcement uses IMEI + cell-tower triangulation for forensic localization.

Tampering with IMEI is a criminal offense

Modifying the IMEI of a handset is illegal in most jurisdictions: in Brazil it falls under Lei 12.737/2012 (Carolina Dieckmann Law) and the Codigo de Telecomunicacoes; in the United States it is prosecuted under the CFAA and the Wireless Telephone Protection Act; in the European Union, Directive 2002/58 plus national laws criminalize the practice. Even possessing an IMEI-flashing tool can constitute evidence of intent.

An IMEI that fails the Luhn checksum is a strong indicator of cloning or sloppy reprogramming. A valid checksum, however, only proves the number is well-formed — it does not prove the GSMA actually allocated that TAC, nor that the serial corresponds to a real device. Authoritative lookup requires the GSMA Device Check API or a carrier-side EIR query.

FAQ

How do I find my IMEI? Dial *#06# on the dialer; alternatively, look at the SIM tray, the box label, or Settings > About on iOS and Android.

Can this tool tell me if a phone is stolen? No. The validator only verifies the Luhn checksum. To know whether an IMEI is on a blocklist, query your carrier or the official Anatel/SIIIM portal in Brazil.

Does Luhn detect a single swapped digit? Yes — Luhn catches every single-digit substitution and most adjacent transpositions, which is why it is the universal scheme for device IDs.

Is a Luhn-valid IMEI necessarily real? No. Mock IMEIs that satisfy Luhn are routinely generated for unit tests and emulator profiles. Only the GSMA can confirm a real allocation.

What is the difference between IMEI and MEID? MEID is the 14-character hexadecimal identifier used by CDMA networks (Verizon, US Cellular before VoLTE migration); IMEI is the GSM/UMTS/LTE/5G equivalent. Modern dual-mode handsets carry both.