Personal Cell Phones - Recent Questions, Troubleshooting & Support

A PIN Unlock Key (PUK), also known as a Personal Unblocking Code (PUC) is used to reset a Personal Identification Number (PIN) that has been forgotten or lost. Most mobile telephones offer the feature of PIN protection. After switching on the phone, if the PIN security function is active, the user is requested to enter a 4-8 digit PIN enabling the phone's non-emergency calling functions. If the wrong PIN is typed in more than three times, either the SIM card, the device, or both become locked. They can be returned to their original unlocked state by entering a PUK, provided by the service operator after verification. If the wrong PUK is entered ten times in a row, the device will become permanently blocked and unrecoverable, requiring a new SIM card. Cellular phone users are therefore advised by most providers to keep their PUK written down in a safe place separate from the device. The PUK (PUC) is a SIM-specific code assigned by the service provider. It is near-impossible to guess and enter it; thus, if a user does not know his or her PUK and is prompted for it, it should be obtained from the service provider. Once you enter the PUK code, you must set a PIN. The PUK and PUK2 are used to unlock the PIN and PIN2 codes respectively if your SIM card is blocked.