WHAT IS IMEI ?

               The International Mobile Equipment Identity number uniquely identifies an

individual mobile station. The IMEI is unique to every ME (Mobile Equipment)

and thereby provides a means for controlling access to GSM networks based

on ME types or individual units.

             The IMEI format is being originated by the Mobile Telecommunication

Standardisation Authorities. Nokia cannot bear a responsibility for eventual                   additional cost arising from e.g. updating the company

housekeeping system etc.

The “IMEI” consists of a number of fields totalling 15 digits. All digits have the

range of 0 to 9 coded as binary coded decimal. Values outside this range are

not permitted.

The IMEI structure valid since 01.04.2004 is as follows

NNXXXXXX                           ZZZZZZ                      A

TAC: Type Allocation Code         SNR: Serial Number    CD: Check Digit

TAC                Type Allocation Code, formerly known as Type Approval Code

NN                  Reporting Body Identifier, e.g. BABT

XXXXXX        Type Identifier defined by Reporting Body

ZZZZZZ          Allocated by Reporting Body but assigned to individual mobile

Stations by the manufacturer

A                     Phase 1 = 0

Phase 2 & 2+ = Check digit, defined as a function of all other

IMEI digits.

IMEI structure until 31.12.2002

The IMEI structure valid until 31.12.2002 is as follows

NNXXXX             YY                 XXXXXX                A

TAC                    FAC               SNR                      CD

TAC: Type Approval Code 

 FAC: Final Assembly Code

SNR: Serial Number  SNR: Serial Number

CD: Check Digit

The meaning of the acronyms for the IMEI format valid until 31.12.2002 is:

TAC Type Allocation Code, formerly known as Type Approval Code

NN                    Reporting Body Identifier

XXXX                ME Type Identifier defined by Reporting Body

FAC                   Final Assembly Code

YY                     Under control of the Reporting Body. May be used to indicate

the manufacturing site. More than one FAC per site should be

used to permit production of greater than 1000000 ME.

A Phase 1 = 0

Phase 2 (0r later) = Check digit, defined as a function of all other IMEI digits.

IMEI structure 01.01.2003 to 01.04.2004

Structure has changed to combine the TAC and FAC into a single eight-digit

TAC code.

 To allow e.g. the operators to modify theirs systems to use the eight digit

TAC rather than a six digit one and the manufacturers to make any

necessary changes to their production processes, a transition period has

been determined to be from 31.12.2002 to 01.04.2004.

To achieve this transition, all eight-digit TAC codes allocated between

31.12.2002 and 31.03.2004 will have unique combinations of the first six

digits (NNXXXX) with the seventh and eight digits (YY) being fixed to 00.

The IMEI structure valid from until 01.01.2003 to 01.04.2004

NNXXXX                  00                  ZZZZZZ              A

TAC                         FAC                SNR                   CD

TAC: Type Approval Code

FAC: Final Assembly Code

SNR: Serial Number

CD: Check Digit