A personal unblocking code (PUC), also known as a Personal Unlocking Key (PUK), is used in 3GPP mobile phones to reset a personal identification number (PIN) that has been lost or forgotten. Most mobile telephones offer the feature of PIN protection. 1) How do you unlock a SIM card that is PUK blocked? Unblock your phone with a PUK code. Your phone can become blocked in a number of ways – one of them is if you enter the wrong SIM card PIN number three times in a row. To unblo