A PUK code, or “PIN unlock key,” is a number that allows you to unblock a locked SIM card. Your SIM card could become blocked if you’ve entered your cell phone’s PIN incorrectly more than three times. Once you’ve entered the wrong PIN three times, a message will display on your phone asking you to enter your PUK code. You can find this code from the online account with your server or you can call your provider directly. Writer Bio
