Changing or "patching" the IMEI on a Nokia 1200 is not possible through a simple keypad secret code. While many online "guides" suggest codes like
To alter the IMEI on a Nokia 1200, technicians use specialized hardware boxes connected to a PC (e.g., UFS-HWK, JAF, Cyclone Box). These tools communicate directly with the phone's logic board via an F-Bus cable. nokia 1200 imei change code