How do I resolve issues with SIM card pin or PUK code on my phone?

1. Identify which SIM card you are using.
2. Check the back of your SIM card for the 8-digit PIN or 10-digit PUK code.
3. If PIN/PUK code is missing, contact the service provider who issued the SIM card.
4. Once you get the PIN/PUK codes, enter it in your device to unlock it.