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IMEI Validator

Security

Validate any IMEI number instantly using the Luhn algorithm — confirms the 15-digit format and checksum. Free, client-side, your IMEI is never stored.

Reviewed by the thecalcu.com team · Last updated July 27, 2026

What is a IMEI?

An IMEI Validator checks whether a 15-digit IMEI (International Mobile Equipment Identity) number is structurally correct using the Luhn checksum algorithm. Every mobile device that connects to a cellular network, smartphones, tablets, mobile hotspots, is assigned a unique IMEI by its manufacturer. The IMEI serves as the device's permanent identity on mobile networks worldwide.

A valid IMEI is exactly 15 digits long. The first 8 digits form the Type Allocation Code (TAC), which identifies the manufacturer and device model. Digits 9–14 are the manufacturer's serial number for that device. The 15th digit is a check digit calculated using the Luhn algorithm, the same algorithm used to validate credit card numbers. This check digit allows any software or network to instantly detect single-digit transcription errors.

This validator performs two checks: it confirms that exactly 15 digits are present, and that the Luhn checksum is satisfied. Spaces and hyphens are stripped automatically before checking, so you can paste an IMEI in any common formatting. The tool also identifies which part of the IMEI is the TAC and which is the check digit.

To find your phone's IMEI, dial *#06# or check Settings > About. The IMEI is also printed on the original packaging and, on many devices, inside the SIM tray slot. You can also check your Phone Number Validator for number format verification.

Why Use an IMEI Validator?

The most common reason to validate an IMEI is when buying a second-hand phone. Before purchasing, dialling *#06# on the device and verifying the displayed IMEI matches the box is a basic anti-fraud check. A phone whose displayed IMEI fails the Luhn check may have had its IMEI modified, a red flag for cloned or stolen devices.

For businesses importing or selling mobile devices in bulk, validating IMEI lists programmatically before CEIR registration prevents rejected submissions. For insurance claims, a correctly formatted IMEI is required before the claim can be processed.

Who Should Use This Validator?

Individuals buying second-hand phones, verify the IMEI structure matches the box before handing over money.

Mobile retailers and importers, validate IMEI batches before bulk CEIR registration or export documentation.

Insurance and telecom support teams, confirm an IMEI is structurally valid before processing a claim or support ticket.

Developers building device management systems, validate IMEI input fields before writing to a database or calling an IMEI lookup API.

What Insights Does the IMEI Validator Give You?

A valid result confirms the 15-digit length and Luhn checksum, and identifies the TAC (first 8 digits) and check digit. This is enough to confirm the IMEI is well-formed and likely genuine.

An invalid result tells you specifically what is wrong: incorrect digit count, or a Luhn checksum failure. A checksum failure on a correctly-length IMEI often means a single digit was mistyped. This tool does not check whether a device is blacklisted, blocked, or registered in any network's CEIR database. Use your operator's official portal for that check.

How to use this IMEI calculator

  1. Dial *#06# on your phone, or find the IMEI in Settings > About Phone.
  2. Copy the 15-digit IMEI number.
  3. Paste it into the IMEI Number field on this page.
  4. The validator runs instantly, no button press needed.
  5. Check the Valid / Invalid badge below the input.
  6. If valid, read the details: TAC, check digit confirmation, and Luhn pass.
  7. If invalid, check whether you have exactly 15 digits and no missing characters.

Formula & Methodology

IMEI validation uses two checks:

1. Length check: the IMEI must be exactly 15 digits (spaces and hyphens are stripped first).

2. Luhn algorithm:
- Starting from the rightmost digit (the check digit), double every second digit moving left
- If doubling produces a value greater than 9, subtract 9
- Sum all digits (original + doubled)
- A valid IMEI produces a total sum divisible by 10

Valid example: 490154203237518, 15 digits, Luhn sum = 40 (divisible by 10) ✓

Invalid example: 490154203237519, 15 digits, but Luhn sum = 41 (not divisible by 10) ✗

Related Tools

You may also find these useful: Credit Card Number Validator.

Frequently Asked Questions

IMEI stands for International Mobile Equipment Identity, a unique 15-digit number assigned to every mobile device globally. It is used by networks to identify devices, block stolen phones from accessing services, and for warranty and insurance purposes. No two active mobile devices share the same IMEI.
The quickest way is to dial *#06# on your phone, the IMEI appears on screen immediately. You can also find it in Settings > About Phone (Android) or Settings > General > About (iPhone). It is also printed on the original box and, on older phones, under the battery.
The Luhn algorithm (also called Modulus 10) is a simple checksum formula used to validate identification numbers. Starting from the rightmost digit, every second digit is doubled; if doubling produces a number greater than 9, subtract 9. Sum all digits, a valid IMEI produces a sum divisible by 10. The Luhn check catches common single-digit transcription errors.
It checks two things: that the IMEI is exactly 15 digits, and that the final check digit satisfies the Luhn algorithm. Spaces and hyphens are stripped automatically before checking. This confirms the IMEI is structurally well-formed, it does not verify the device is registered, active, or unblocked on any network.
No. This tool checks the format only, it confirms the 15-digit structure and Luhn checksum. Whether a device is blacklisted, blocked, or reported stolen is determined by network operator databases (such as CEIR in India), which are not accessible from a browser. Use your network operator's official CEIR portal to check a device's status.
No. All validation runs entirely in your browser, nothing is sent to any server, stored, or logged. IMEI numbers are sensitive device identifiers, so client-side processing is a firm requirement for this tool.
The first 8 digits of an IMEI form the Type Allocation Code (TAC). The TAC identifies the device model and manufacturer, it is assigned by the GSMA. The remaining 6 digits (positions 9–14) are the serial number assigned by the manufacturer, and the final digit is the Luhn check digit.
Theoretically no, IMEIs are supposed to be globally unique. In practice, counterfeit or cloned phones sometimes share IMEIs, which is illegal in most countries. Duplicate IMEIs can cause network authentication failures and are one of the indicators of device counterfeiting.
CEIR (Central Equipment Identity Register) is India's national IMEI database, maintained by the Department of Telecommunications (DoT). It records all IMEIs of mobile devices in India and allows users to block stolen devices via the Sanchar Saathi portal. A structurally valid IMEI can still be blocked or unregistered in CEIR, this validator does not check CEIR status.
Check that you copied all 15 digits correctly, a missing or extra digit is the most common cause. Redial *#06# to get the IMEI directly from the device rather than reading it off the box. If the IMEI still fails the Luhn check after careful re-entry, the device may have a corrupted or cloned IMEI, which should be reported to your network operator.
Yes. Any device that connects to a cellular network, tablets, mobile hotspots, some laptops, is assigned an IMEI. Wi-Fi-only tablets do not have an IMEI because they do not connect to cellular networks. The IMEI format and validation rules are the same regardless of device type.
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