A PUK code for a SIM card, which stands for Personal Unblocking Key, is an eight-digit code that enables a blocked SIM card to be unlocked. When a user repeatedly enters a wrong PIN code, such as ...

PUK is the code required to unlock a GSM SIM card that has disabled itself after an incorrect PIN code was entered 3-5 times in a row. If an incorrect PUK code is entered a certain number of times ...

After changing the SIM, you will be prompted to “Enter SIM PIN.” After three incorrect PIN attempts, users are prompted to enter the PUK code, which you should know because it’s your SIM card.

Swap out the SIM and then you’ll have to “Enter SIM PIN.” After three wrong PIN attempts, users are asked for the PUK code, which you’ll be aware of since it’s your SIM card.