This setting of mobile phone SIM card is mainly to protect personal mobile communication business and prevent SIM card from being stolen by others, causing high expenses and unnecessary losses to users.
If you want to know your PIN code and PUK code, you can log in to China Mobile website with your mobile phone number and service password, and automatically enter the personal customer webpage. Then find "online business hall-bill inquiry-personal information setting -SIM card information inquiry -SIM card information", where you can see the PIN1/pin2/puk1/puk2 code of the mobile phone.
In addition, there are many channels for electronic products to set PIN codes to protect personal information. There are generally two kinds of unlock pin codes: one is the unlock pin code of SIM card to prevent SIM card from being stolen by others and wasting your mobile phone fee; The second is to unlock the PIN code, which can also prevent others from accessing your mobile phone desktop at will and protect your personal information. In addition, there are other security PIN codes, such as the factory reset PIN code, which can prevent your mobile phone from being inadvertently restored to the factory state and losing your personal information, so when you want to restore it, you will be prompted to enter the PIN code to play a warning role. These codes can be the same or different. Generally, they are set the same, which is convenient for memory.
The PIN code is generally a four-digit password, and the default is "0000" or "1234".
I don't know if you understand.
Good luck!