If you fail to input the correct SIM card PIN code three consecutive times, the PIN will be blocked and your phone will request you to enter a PUK (Personal Unlocking Key) code.
How to find your PUK code
Option 1: If you still have the plastic container tray which housed your SIM card when it arrived, the PUK code will be written on it.
Option 2: Contact your Network provider.
Inputting your PUK code
1. Before attempting to input your PUK code, ensure that you have the correct code provided by your Network provider.
2 .After ten unsuccessful attempts to input your PUK code, the SIM card will be permanently disabled.
3.Once the SIM card is permanently disabled, you will need to contact your Network provider for a new SIM card.