Security Master Code For DCT-3 and DCT-4 phones.
All the users who have forgotten their Security/Lock Codes need not worry. You just need to know your IMEI (International Mobile Equipment Identity) number.
To check your IMEI number, type *#06# on the main screen. This number can also be found on the backside of the handset. Just remove the battery.
You can visit a site which will calculate the Master Code of your phone. This code can be used to change your present Lock/Security code.
Nokia Lock Code
Note :
1. Lock/Security Code is not the PIN Code.
2. If you want to remove the Service Provider Lock, then this is not what you are looking for.
3. The Master Codes are only for DCT-3 and DCT-4 phones.
Check this list if you are not sure if your phone is DCT-3 or DCT-4
Nokia DCT Check List
"Remember This is for DCT-3 & DCT-4 Nokia phones only it will not work on DCT-5 or BB5 Models."
Also neither i, nor Mobiles24, can guarantee 100% accuracy.