If the codes do not work, it usually means the firmware is heavily corrupted. In this case, you cannot change the IMEI simply by typing a code. You will need to use a flash tool.
The one universal code that functions flawlessly across all mobile phones, including every version of the Nokia 105, is *#06# . You simply open the dialer, type in this sequence, and press the call button. The phone will immediately display its 15-digit International Mobile Equipment Identity (IMEI) number on the screen. nokia 105 ta 1203 imei change code
Attempting to change a device identity code to a random sequence or cloning an existing phone's serial number carries heavy risks: If the codes do not work, it usually