Your IMEI looks like a random 15-digit number, but it is far from random. Every section carries specific information about your device. The most important part is the first 8 digits — the TAC code — which uniquely identifies your phone's make and model to the entire global mobile industry.
TAC stands for Type Allocation Code. It is the first 8 digits of your IMEI, assigned by the GSMA to a specific device model. Every iPhone 15 Pro ever made shares the same TAC code.
Breaking down the IMEI structure
What does each section mean?
Digits 1–2: Reporting Body Identifier
The first two digits of the TAC identify which GSMA-accredited body allocated the IMEI range. Common values include:
- 35 — BABT (UK), one of the most common allocators globally
- 86 — China's allocation body, used by Xiaomi, Huawei, OnePlus
- 01 — Used by some North American manufacturers
This is why so many Apple and Samsung devices start with 35 — it does not mean they are made in the UK. It means the GSMA allocation for those models was processed through the UK reporting body.
Digits 3–8: Model identifier
The remaining 6 digits of the TAC, combined with the first 2, create a unique 8-digit code that maps to a specific device model. These are assigned by the GSMA when a manufacturer applies for a new device certification. A manufacturer may have hundreds of TAC codes — one for each model variant, color, or regional version.
Digits 9–14: Serial number
This 6-digit section is the manufacturer's serial number for the specific unit. Combined with the TAC, it makes the full IMEI globally unique.
Digit 15: Luhn check digit
The final digit is not random — it is mathematically calculated from the previous 14 digits using the Luhn algorithm. This allows any system to instantly verify whether an IMEI is correctly formed without needing to look it up in a database.
Common TAC prefixes by brand
| TAC prefix | Brand | Notes |
|---|---|---|
| 35299, 35879, 35384, 35388 | Apple | Various iPhone models |
| 35260, 35937, 35131 | Samsung | Galaxy S, A, Z series |
| 8649, 8645 | Xiaomi / Poco | Mi, Redmi, Poco series |
| 8676, 8698 | Huawei | P, Mate, Nova series |
| 3553, 3556 | Pixel series | |
| 3585, 3586 | Sony | Xperia series |
| 8649 | OnePlus | Shares range with Xiaomi |
Why does the TAC matter for IMEI checking?
The TAC is the key that lets IMEI checkers identify your device without needing access to carrier databases. When you enter an IMEI on our site, we extract the first 8 digits and match them against a database of TAC-to-model mappings maintained by the GSMA and published by manufacturers.
This is also why our checker can identify the device even when it cannot access blacklist databases — the TAC alone tells us the brand and model.
What if my TAC is not recognized?
There are a few reasons a TAC might not be in our database:
- The device is very new and the TAC has not been published yet
- It is a regional variant with a unique TAC for a specific market
- It is an obscure or low-volume device model
- The IMEI may be incorrect or non-standard
An unknown TAC does not necessarily mean the device is fake — but if the IMEI also fails the Luhn check, that is a strong indicator something is wrong.
See your TAC code now
Enter your IMEI and we will decode the TAC to show you your device brand and model.
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