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

Every IMEI number tells a story, and the first eight digits write the opening chapter. That eight-digit prefix is the Type Allocation Code, or TAC — the part of the IMEI that says what a device is before any serial number identifies which unit you are holding.

If you have ever wondered why two phones of the same model share the same opening digits, or how a carrier can recognize an iPhone 15 Pro from its IMEI alone, the answer is the TAC. This guide breaks down exactly what a Type Allocation Code is, who assigns it, how to read one, and why it sits at the heart of every random IMEI you generate.

TAC in One Sentence

A Type Allocation Code is the first 8 digits of a 15-digit IMEI that uniquely identifies the manufacturer and model of a mobile device.

Here is where it lives inside a full IMEI:

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

The TAC never changes for a given device model. Every Galaxy S24 Ultra sold worldwide carries the same TAC; only the six serial digits in the middle differ from one handset to the next.

Who Assigns TAC Codes?

TACs are not random. They are issued by the GSMA (GSM Association), the global industry body that coordinates mobile operators and manufacturers. Through its administrative arm, the GSMA runs the official IMEI database and hands out TAC ranges to approved device makers.

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. The GSMA verifies the application and assigns one or more eight-digit TAC values to that exact model.
4. The manufacturer burns the TAC into every unit's IMEI during production.

Because the GSMA is the single authority, TACs are globally unique. No two unrelated device models share a TAC, which is what makes the system reliable for identification.

A single popular model can be assigned multiple TACs. High-volume phones often exhaust the serial space of one TAC and roll onto additional ones, which is why the iPhone or a flagship Galaxy may have several valid TAC prefixes in circulation.

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 narrows it down to a specific manufacturer and device family

You do not need to decode this by hand. TAC lookup databases map the full eight-digit code straight to a brand and model name. But knowing the structure helps you understand why the first couple of digits look familiar across many different phones.

Why the TAC Matters

The TAC is small, but it does a lot of work across the mobile ecosystem.

Device Identification

When a phone registers on a network, the carrier reads the IMEI and uses the TAC to know exactly which model just connected. This drives everything from VoLTE compatibility to band support and warranty lookups.

Blacklist and Theft Databases

Stolen-device registries are indexed by full IMEI, but the TAC tells investigators the model of a flagged handset at a glance. Learn more in our guide to the IMEI blacklist check.

Insurance and Trade-In Valuation

Buy-back and insurance platforms read the TAC to auto-detect a device's make, model, and approximate value without asking the user to type it in.

Realistic Test Data

This is where TACs intersect with testing. To generate IMEI numbers that look and behave like real devices, you need authentic TAC prefixes. A random 15-digit number with a made-up prefix will not match any known model and may be rejected by software that performs TAC lookups. That is exactly why the Random IMEI generator draws from curated, real-world TAC pools rather than inventing prefixes.

TAC vs. the Rest of the IMEI

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

The TAC answers "what kind of device is this?" The serial answers "which one?" And the check digit confirms the whole number was transcribed correctly. If you want to verify that a complete number is well-formed, the IMEI validator runs the Luhn check and decodes each section for you.

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

For QA engineers, fraud analysts, and developers, the TAC is the ingredient that separates believable test data from noise. A good IMEI generator does three things with TACs:

1. Sources real prefixes. It maintains a catalog of genuine TAC values mapped to actual device models, refreshed as new phones launch.
2. Aligns the model to the TAC. When you pick "Samsung Galaxy S24 Ultra," the generator selects a TAC that genuinely belongs to that model — not a generic placeholder.
3. Builds a valid number on top. It appends a random six-digit serial and computes the Luhn check digit so the final IMEI passes validation.

The result is a number that behaves like a real device in activation flows, marketplace listings, and fraud filters — without ever pointing to a physical handset. You can try it on the Random IMEI homepage or jump straight to a brand-specific generator if you need IMEIs for a particular lineup.

FAQ

What does TAC stand for?

TAC stands for Type Allocation Code. It is the first eight digits of an IMEI and identifies the manufacturer and model of a mobile device.

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?

Two phones of the same model share the same TAC. Two different models never share a TAC, because the GSMA assigns each one uniquely. However, a single high-volume model may be issued several TACs as serial ranges fill up.

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?

Several public TAC lookup databases map eight-digit codes to brand and model names. The official source is the GSMA's IMEI database, while third-party sites offer free reverse lookups for common consumer devices.

Why do generated IMEIs need real TAC codes?

Software that performs TAC lookups (activation services, marketplaces, fraud filters) checks the prefix against known models. A made-up prefix fails that check. Using authentic TACs — as the Random IMEI generator does — produces test numbers that behave like genuine devices.