How to use a SIM card PIN to protect others from using your iPhone or iPad every time you restart or remove your SIM card. The SIM will automatically lock and you will see the message “SIM Locked” in the status bar.
To enable or disable the SIM PIN code
1. On iPhone, go to Settings > Cellular > SIM PIN, and on iPad, go to Settings > Cellular Data > SIM PIN.
2. Turn the SIM PIN code on or off.
3. The device will be prompted to enter the SIM PIN code. If you have never used it before or have not changed it before, enter the default SIM PIN provided by your carrier. But if you don’t know the default PIN code of the SIM, you don’t try to guess Check the information on the package. You bought the SIM card in or contact your carrier.
The default PIN for each SIM card is
- AIS: 1234
- True: 0000
- dtac: 1800
After SIM PIN is enabled, when you turn the phone off and on or remove the SIM card from the phone and insert it again, the screen will show “SIM Locked” or the status bar will say “SIM Lock” which will not be able to use calls and can’t use the internet. until enter unlock with PIN code
To activate a normal SIM card, enter the PIN code you have set. Only then will be able to use the SIM normally.