What Is IMEI TAC and FAC Terms

About ME Type and GSM ME

Term ME is usually defining the mobile device that is identified with unique IMEI number. ME stands for Mobile Equipment and it is describing the GSM gadgets that are available in the market. This sounds pretty simple, isn’t it?

There are many hardware platforms on which GSM Mobile Equipment models are based. They are manufactured by different companies and have different ME Type. You can guess that ME Type models can get changes in hardware design, enhancements and other things manufacturing process add to devices. The companies are using ME Build Level and give their products different build numbers to reflect the changes.

Devices are allocated an IMEI – this process is known as Type Allocation. The GSM Association appoints organizations [they are referred to as Reporting Body] that have the authority to allocate IMEI numbers to different ME Types [you can find out if your iPhone IMEI is valid or not]. This happens in every country and there might be several Reporting Bodies in the same area. These Reporting Bodies not only have the right to allocates IMEIs but can also permit the use of device on your network using its IMEI code.

We know that this could sound complicated but these are details about IMEI number that can help you understand this term and its nature. So let’s put everything in simple words: ME is the device that has the IMEI code which was allocated by Type Allocation Holder which is not always your original ME manufacturer.

IMEI TAC FAC Guide ME

Term ME is usually defining the mobile device that is identified with unique IMEI number. ME stands for Mobile Equipment and it is describing the GSM gadgets that are available in the market. This sounds pretty simple, isn’t it?

There are many hardware platforms on which GSM Mobile Equipment models are based. They are manufactured by different companies and have different ME Type. You can guess that ME Type models can get changes in hardware design, enhancements and other things manufacturing process add to devices. The companies are using ME Build Level and give their products different build numbers to reflect the changes.

Devices are allocated an IMEI – this process is known as Type Allocation. The GSM Association appoints organizations [they are referred to as Reporting Body] that have the authority to allocate IMEI numbers to different ME Types [you can find out if your iPhone IMEI is valid or not]. This happens in every country and there might be several Reporting Bodies in the same area. These Reporting Bodies not only have the right to allocates IMEIs but can also permit the use of device on your network using its IMEI code.

We know that this could sound complicated but these are details about IMEI number that can help you understand this term and its nature. So let’s put everything in simple words: ME is the device that has the IMEI code which was allocated by Type Allocation Holder which is not always your original ME manufacturer.

IMEI TAC FAC

Now as we got acquainted with main terms associated with IMEIs – let’s get back to the number structure and take a closer look at AB-CDEFGH-IJKLMN-Z format familiar to millions of iPhone and other mobile device owners.

The historical IMEI structure contained TAC, FAC, Serial number and Check digit. Such structure was valid till December 31st, 2002. TAC used to be Type Approval Code and is now the Type Allocation Code. FAC was the Final Assembly Code. If we return to our main formula, we’ll see that:

• * AB standed for TAC code [or Reporting Body Identifier]
• * CDEFGH standed for the remainder of TAC [FAC]: CDEF referred to ME Type Identifier and GH could indicate the manufacturer and was under control of the Reporting Body
• * IJKLMN was the serial No [it was Allocated by Reporting Body however only manufacturers could assign it to ME models]
• * Z was the check digit [it defines as a function for all IMEI codes]

Then the industry decided to change this IMEI structure and TAC + FAC were combined into the single 8-digit TAC code [the FAC had to be considered as obsolete]. It is understood that such changes couldn’t happen within one or two days. There was a 2-year transition period between December 31st, 2002 and April 1st, 2004.