If you need to check your current IMEI, simply dial *#06# . If it is valid, leave it alone.
: Attempting to use unauthorized "IMEI repair" software can permanently damage the phone’s firmware, leading to a "Contact Service" error or a total "bricked" state. Network Blacklisting nokia 1200 imei change code
On a modern smartphone, the IMEI is also tied to the motherboard. On a feature phone like the Nokia 1200, the IMEI is stored in a specific chip called the (Non-Volatile Random Access Memory) or the flash chip that holds the firmware. If you need to check your current IMEI, simply dial *#06#