International Mobile Station Equipment Identity

The International Mobile station Equipment Identity (IMEI ) is a unique 15 - digit serial number to every GSM or UMTS device can theoretically be clearly identified. Dual - SIM phones have two IMEI numbers.

In the general public, the IMEI is known by the alleged Ability to disable a stolen mobile phone in the mobile network operators. In theory, the phone is not usable after blocking with a different SIM card. To this end, the affected IMEIs be performed in lists. However, the IMEI is unsuitable for theft protection, as can reprogram the IMEI of a mobile phone with appropriate software. Further details on these lists and their poor suitability for theft protection see Equipment Identity Register (EIR ).

The IMEI should be kept to the terminal to report as stolen in case of theft to the police. The IMEI is also often needed to remove a SIM lock.

Query

The IMEI of a mobile phone can be retrieved by entering * # 06 # in the box of the phone number. This key code is uniform prescribed in the GSM - standard.

On many phones you can find the IMEI on the nameplate. It is usually located under the battery.

In older Ericsson and most Sony Ericsson models, the IMEI can also be accessed with the following key combination: * → * ← ← ← *.

Format

IMEIs from clients who were admitted from April 1, 2004, consist of three parts:

• The first eight digits form the TAC (Type Allocation Code ). The first two digits of the TAC are made of a Reporting Body Identifier ( RBI) and point to the permitting accreditation body. The remaining six digits contain the authorization code. The TAC is unique for different mobile devices and hardware can be used to identify a terminal type.
• The next six digits are the actual serial number of the terminal ( SNR).
• The last digit is the check digit CD ( Check Digit ). In GSM Phase 1 devices it is '0 ', Phase 2 it is busy. The check digit is only stored in the device, with transmission in the network is always a '0 'is transferred. The algorithm for the calculation is documented in 3GPP TS 23.003, Appendix B.

By 2002, the TAC was six digits only and provided information about the manufacturer. This was followed by a two-digit Final Assembly Code (FAC ) with an additional manufacturer - specific identifier. During the transition period from January 2003 to the end of March 2004, two zeros were used instead. Both places are since April 2004 TAC.

Some devices also still have a two-digit identifier of each object in the device software, the software version number ( SVN). This is not part of the IMEI, but is often spent in search * # 06 # with.

Uniqueness of the IMEI in practice

Whereas the standard stipulates that a clear and IMEI is protected from tampering by the user, this is not the case in practice. For many on the market since 2002 devices to manipulate the IMEI is possible. A spokesman was known in 2002 told the BBC that about 10 % of IMEIs in the cellular network to BT Cellnet (O2) are not clear. The GSMA itself puts the responsibility for compliance with the standards and the uniqueness of the IMEI and protection against manipulation of these in the hands of the equipment manufacturers, but admits that the standards are particularly outside the European Union inadequately applied. The fact that a large part of the device manufacturers outside the EU are located, makes it clear that a certainty and clarity of IMEIs is not guaranteed.