What Is a TAC (Type Allocation Code)? IMEI's First 8 Digits

The first eight digits of a 15-digit IMEI form the Type Allocation Code (TAC). Software can map that complete prefix to an allocated equipment type when it has an authoritative or explicitly versioned data source.

Software can compare the full TAC with an authoritative or locally supplied mapping to classify a device type. This guide explains what a Type Allocation Code is, how allocation works, and why a generated prefix is not itself an authenticated device record.

TAC in One Sentence

A Type Allocation Code is the first 8 digits of a 15-digit IMEI. It is allocated for an approved device type and can be mapped to manufacturer and model information through an appropriate database.

Here is where it lives inside a full IMEI:

35 824011  345678  4
└── TAC ──┘ serial  check
 (8 digits) (6)     (1)

A device model can have several TACs across regions, hardware revisions and production ranges. Units covered by the same TAC then differ in the six-digit serial portion.

Who Assigns TAC Codes?

Production TACs are allocated through the GSMA ecosystem and its appointed reporting bodies under documented IMEI allocation rules. The authoritative Device Database is not the same thing as a public list copied into a generator.

The process looks roughly like this:

1. A manufacturer (Apple, Samsung, Xiaomi, etc.) develops a new device model.
2. Before that model can connect to cellular networks, the maker applies to the GSMA for a TAC.
3. An authorized reporting body processes the application and allocates one or more eight-digit TAC values for the approved device type.
4. The manufacturer burns the TAC into every unit's IMEI during production.

The allocation system is designed so a TAC refers to one approved device type in the authoritative record. Consumer marketing names, regional variants and later corrections can make a simple one-name lookup less precise than that record.

One marketed model may appear under several TAC records because allocations can differ by variant or production range. The authoritative record, rather than a retail name, determines the mapping.

How to Read a TAC

Within the eight-digit TAC, the digits carry meaning:

So in the TAC 35824011:

• 35 is the Reporting Body Identifier
• 824011 completes this example TAC; a mapping database is required to attach a device label

Do not decode manufacturer or model from either segment in isolation. Compare all eight digits with a source whose authority, license and revision date fit the use case.

Why the TAC Matters

Systems use TAC mappings for several distinct purposes, each with different data requirements.

Device Identification

A network or inventory system can compare the TAC with its current database to classify the equipment. The TAC alone does not prove radio capability, warranty status, ownership or network eligibility.

Blacklist and Theft Databases

A blocklist result applies to the full IMEI returned by the chosen provider. TAC may be one field in that provider's device metadata, but a TAC alone has no blocklist status. See the IMEI blacklist check guide.

Insurance and Trade-In Valuation

A buy-back or insurance workflow may compare TAC with licensed device data, then combine the result with condition, storage, region and its own eligibility rules. TAC alone does not establish value or coverage.

Realistic Test Data

TAC-aware fixtures can exercise parsing and device-label branches in your own software. Their behavior depends on the mapping supplied to the test. A Luhn-valid value does not authenticate a device or predict the result of a carrier, activation, marketplace or fraud-system lookup.

TAC vs. the Rest of the IMEI

It helps to see the TAC alongside the other IMEI components:

The TAC can identify an allocated equipment type in the source database; the serial differentiates equipment identities within that allocation. The check digit helps detect entry errors but does not confirm assignment or device status. The IMEI validator tests only format and Luhn.

A Brief History of the TAC

The TAC has not always been eight digits. In earlier GSM specifications, the IMEI used a 6-digit TAC followed by a separate 2-digit Final Assembly Code (FAC) that indicated the factory where the device was assembled.

Around 2004, the GSMA simplified the format: the FAC was absorbed into the TAC, producing the 8-digit TAC used today. Modern IMEIs no longer encode the assembly plant separately — those two digits are now part of the model identifier. If you ever read older documentation referring to a "6-digit TAC plus FAC," that is why it looks different from current numbers.

How TACs Power Synthetic IMEI Generation

Random IMEI uses TAC inputs in three transparent steps:

1. Selects a snapshot prefix. The site uses a manually curated, non-authoritative catalog dated 2025-11-02.
2. Applies the local label. A selected manufacturer and model determine which prefix pool the site uses; the mapping is not an official lookup.
3. Builds a Luhn-valid value. It appends a random six-digit serial and computes the check digit.

The result is only a structurally valid fixture. Random IMEI does not query GSMA, carriers or blacklists and cannot rule out a collision with an assigned identifier. See the methodology, keep outputs in isolated tests and never submit them to live identity systems.

TAC mapping QA cases

Developers can review the snapshot methodology, confidence contract and limitations. Every current mapping is explicitly marked legacy-unverified; the raw catalog is not offered as a public dataset because its original provenance and reuse license are not established.

FAQ

What does TAC stand for?

TAC stands for Type Allocation Code. It is the first eight digits of an IMEI and maps to an allocated equipment type when interpreted through an appropriate database.

How many digits is a TAC?

A modern TAC is 8 digits long. Older GSM devices used a 6-digit TAC paired with a separate 2-digit Final Assembly Code, but the format was consolidated into 8 digits around 2004.

Can two different phones have the same TAC?

Devices covered by one allocation can share a TAC, and one marketed model can have several TACs. Treat the authoritative allocation record—not a marketing-name guess—as the source of truth for whether two variants belong to the same device type.

How do I find the TAC of my phone?

Dial *#06# to display your full IMEI, then read the first eight digits — that is your TAC. You can paste the complete IMEI into the IMEI validator to see the TAC and other components broken out.

Is a TAC the same as an IMEI?

No. The TAC is only the first 8 digits of an IMEI. A complete IMEI is 15 digits: the 8-digit TAC, a 6-digit serial number, and a 1-digit Luhn check digit.

Where can I look up which device a TAC belongs to?

The authoritative allocation data is held in the GSMA Device Database. Other datasets may be incomplete, stale or differently licensed, so document the exact source and revision used by your workflow.

How should a test generator use TAC inputs?

Choose a TAC source appropriate to the test and document its date, authority and limitations. Random IMEI uses a dated local snapshot for repeatable fixtures; it is not a substitute for the official GSMA database or a licensed production lookup.