Your device's SIM card will be locked if you enter your PIN incorrectly several times. 

You can unlock the SIM card by entering PUK 1. 
You can usually find PIN and PUK 1 on the card carrier of your SIM card.
If you also enter PUK 1 incorrectly several times, you can only unlock the SIM card with PUK 2. 
You can usually request PUK 2 from your SIM card provider.


The device requires you to enter the PIN when you use a SIM card for the first time and normally every time you restart the device. You can change the PIN of the SIM card in the settings of your device. You can also specify whether the PIN must be entered when the device is restarted.

The PIN of the SIM card is not linked to the unlock function of the display. To unlock the display, enter a separate unlock code, pattern or other.

Caution when using dual SIM on mobile devices: Do not mix up the PINs of the individual SIM cards!