The IMEI, short for International Mobile Equipment Identity, is a unique number given to every single mobile phone. It is not modifiable by the user and a written copy of it can typically found behind the battery. It can also be displayed on screen by entering the *#06# key sequence.
Depending on your mobile, this number can have two different formats (the old and the new format:
aabbbb-cc-dddddd-e if your mobile has been manufactured before April 1st 2004. xxxxxxxx-dddddd-e if your mobile has been manufactured after this date.
The old IMEI format
The format aabbbb-cc-dddddd-e was in use until April 1st 2004. Its meaning is: aabbbb is the Type Approval Code (TAC). The first two digits (aa) represent the country code.
The second group of numbers (cc) is the Final Assembly Code (FAC). This identifies the device manufacturer:
| 01,02 = | AEG | 60 = | Alcatel | ||
| 07,40 = | Motorola | 61 = | Ericsson | ||
| 10,20 = | Nokia | 65 = | AEG | ||
| 30 = | Ericsson | 70 = | Sagem | ||
| 40,41,44 = | Siemens | 75 = | Dancall | ||
| 50 = | Bosch | 80 = | Philips | ||
| 51 = | Sony, Siemens, Ericsson | 85 = | Panasonic |
dddddd represents the device serial number (SNR)
the last single digit (e) is an check digit (usually set to 0).
The new IMEI format
The new format xxxxxxxx-dddddd-e is used since 1st April 2004. The FAC value has disappeared and the Type Approval Code has been be replaced by a Type Allocation Code (TAC in both cases): xxxxxxxx is a eight digit number: the Type Allocation Code. dddddd and e have the same meaning as in the old format.
The IMEISV format
You may have two extra digits at the end of the IMEI. IN this case, these two additional numbers reflects the software version number of your phone. You can check in ETSI specs 02.16 and 03.03 if you need to have more details.