When you run an IMEI check and it correctly identifies your phone as a specific model with specific hardware, that is the TAC code doing the work. The TAC is the intelligence embedded in every IMEI, and understanding it helps explain how IMEI-based lookups work.
What Does TAC Stand For?
TAC stands for Type Allocation Code. It is the first 8 digits of every 15-digit IMEI number. The TAC identifies a specific device type from a specific manufacturer — not a single device, but a model class.
Every unit of the same model from the same manufacturer shares the same TAC. Every iPhone 16 Pro Max (global variant) has the same 8-digit TAC prefix. Every Samsung Galaxy S25 Ultra has its own shared TAC.
How TAC Numbers Are Allocated
TAC numbers are allocated by the GSMA — the international mobile standards body. Manufacturers apply for TAC numbers before production begins, submitting detailed device specifications as part of the application. The GSMA maintains the IMEI Database (IMEI DB), which associates each TAC with the device specifications provided by the manufacturer.
A manufacturer making many different models holds many TACs. Apple, Samsung, and Huawei each hold hundreds of TAC allocations covering their various device models, variants, and generations.
What a TAC Lookup Reveals
When you look up an IMEI, the TAC portion returns:
Manufacturer: The company that produced the device (Apple, Samsung, Huawei, Xiaomi, etc.)
Model name: The specific product (iPhone 15 Pro, Galaxy S24+, etc.)
Model number: The internal model designation (A2848 for a specific iPhone variant, SM-S928B for a Galaxy S24 Ultra global model, etc.)
Device type: Smartphone, tablet, mobile broadband device, etc.
Frequency bands: Which radio bands the device supports (critical for network compatibility verification)
Regional variant: Which market the device was manufactured for
Why Different Variants Have Different TACs
A Samsung Galaxy S25 sold in the UK has a different TAC from the same phone sold in the US. This is because they are technically different hardware variants — the US model may support different 5G frequencies, have different cellular modem firmware, and carry different regulatory certifications.
TAC-level identification allows:
- Precise model verification (confirming a seller's claim about a device)
- Regional variant identification (identifying an imported device vs a locally sold one)
- Band compatibility assessment (checking whether an imported phone works on local networks)
- Insurance and warranty management (exact model identification for claims)
TAC vs IMEI — The Distinction
The TAC (8 digits) identifies the device type. The full IMEI (15 digits) identifies the specific unit:
- TAC (digits 1-8): Model identifier — same for all devices of that model/variant
- Serial (digits 9-14): Unit identifier — unique to each individual device
- Check digit (digit 15): Mathematical validation
When you look up just the TAC (the first 8 digits of an IMEI), you get model information. When you look up the full IMEI, you additionally trigger database queries against carrier records, blacklists, and device-specific data.
The GSMA IMEI Database
The GSMA maintains the authoritative TAC database. Access to the full database requires registration and is used by carriers, governments, and authorised service providers. Public tools like DeviceDecoded use the publicly available TAC data plus additional layered databases to provide comprehensive device checks.
Using TAC Information Practically
Verifying a device's claimed model: If a seller claims a device is an iPhone 15 Pro Max but the TAC lookup returns iPhone 15 (standard), the claim is false.
Checking regional variant: A TAC showing a Chinese variant when you expected a UK model reveals the device may lack UK-specific bands or certifications.
Network compatibility: TAC data includes the device's supported frequency bands. Cross-referencing with your carrier's band requirements confirms whether an imported or secondhand device will work on your network.
Identifying counterfeits: Counterfeit devices often use invalid TAC codes, or TACs that do not match the device's claimed model. An IMEI check that returns a TAC for "Generic Android Device" when the phone claims to be a Samsung Galaxy is a strong indicator of counterfeiting.
How to Look Up a TAC
Simply use the full IMEI — a TAC lookup is automatically part of any IMEI check. Enter the 15-digit IMEI at DeviceDecoded's IMEI Check and the model identification is returned as part of the standard results. You do not need to separately extract and look up the TAC — it happens automatically.