View Full Version : Last digit of IMEI
GSMJoker
07-15-2002, 03:54
Hi.Maybe somebody can share with IMEI last digit calculating
algo?
greenapple
07-19-2002, 09:24
i found a document b4.. about how the last digit of imei is calc. i will email it to you...
:) :) :)
Dear greenapple
Could you please send me the document too!
Many thanks
AlQuds
email: harbm@msn.com
Pls. Also send it to me...
Mikkel@Mpdata.dk
Regards
Squid
Originally posted by greenapple
i found a document b4.. about how the last digit of imei is calc. i will email it to you...
:) :) :)
To me too plz :D
tnx ;)
greenapple
07-24-2002, 09:33
sent... :)
Hi everyone,
The 'solution' was posted a long time ago in this forum.
Anyway, for all of you who missed it, here it is again from someone we gonna miss (i'm afraid) :(
do with it what you like.....
------------------------------------------------------------
The last number of the IMEI is called the Check Digit and is defined using a formula called "Luhn formula", thus sometimes the last digit is called the Luhn Check Digit and does not necessarily always set to 0.
This check digit is computed in three steps as follows:
Given:
14 most significant digits of the IMEISV without the SVN which are the 6-digit TAC, 2-digit FAC, and 6-digit SNR and are labelled as follows:
TAC = D14 D13 ... D9 (with D9 the least significant digit of TAC);
FAC = D8 D7 (with D7 the least significant digit of FAC); and
SNR = D6 D5 ... D1 (with D1 the least significant digit of SNR).
Example IMEI: 49015420323751? (ignore the last digit)
FAC: 490154
D14:4
D13:9
D12:0
D11:1
D10:5
D09:4
TAC: 20
D08:2
D07:0
SNR: 323751
D06:3
D05:2
D04:3
D03:7
D02:5
D01:1
CHK: ?
Computation of CHK from the IMEI proceeds as follows:
Step 1: Double the values of the odd labelled digits D1, D3, D5 ... D13 of the IMEI.
.D14:4=4
*D13:9x2=18
.D12:0=0
*D11:1x2=2
.D10:5=5
*D09:4x2=8
.D08:2=2
*D07:0x2=0
.D06:3=3
*D05:2x2=4
.D04:3=3
*D03:7x2=14
.D02:5=5
*D01:1x2=2
Step 2: Add together the individual digits of all the seven numbers obtained in Step 1,
1+8 + 2 + 8 + 0 + 4 + 1+4 + 2 = 30
and then add this sum to the sum of all the even labelled digits D2, D4, D6 ... D14 of the IMEI.
4 + 0 + 5 + 2 + 3 + 3 + 5 = 22
The result is:
30 + 22 = 52
or
4 + 1+8 + 0 + 2 + 5 + 8 + 2 + 0 + 3 + 4 + 3 + 1+4 + 5 + 2 = 52
Step 3: If the number obtained in Step 2 ends in 0, then set CHK to be 0. If the number obtained in Step 2 does not end in 0, then set CHK to be that number subtracted from the next higher number which does end in 0.
Since 52 ends in "2", CHK can't be set to "0". The next higher number that does end in "0" after 52 is 60, so we set:
CHK = 60 - 52 = 8
So the IMEI number is: 490154203237518 and it ends in 8.
P.S. The IMEI number sampled above is fictios and does not reflect nor intended for an existing IMEI number.
[ 10 August 2001: Message edited by: Ice Dragon ]
tnx @greenapple & @DCAvdP
Uvedovle
08-01-2002, 17:00
I use nokia tool 3.21 for check if an imei is valid. Try and you will see. Easy.
Regards