1. On the start screen, select Phone > ...settings.
  2. If you have a dual SIM phone, select the SIM you want.
  3. If necessary, switch SIM security to On and tap change SIM PIN.
  4. Enter your current SIM PIN and tap enter.
  5. Enter your new PIN and tap enter.
  6. When you see the message confirm new SIM PIN, re-enter your new PIN and tap enter.

The new SIM PIN must be 4 to 8 digits long. The PIN code protects your SIM card against unauthorised use and is provided with the SIM card. After three consecutive incorrect PIN code entries, the code is blocked, and you need to use the PUK code to unblock it before you can use the SIM card again. Contact your mobile operator if you do not know the PUK code.

Note: If this is the first time a PIN has been set for the SIM card in your phone, type the PIN code you have got from your operator, and then tap Enter. 1234 is a common default PIN for some SIM cards. If the PIN code does not work, contact your mobile operator for the correct default PIN.