What is the difference between PUK1 and PUK2 codes?

A PUK code or Pin Unblocking Key is used to unblock a SIM. Your SIM card can become locked after three unsuccessful password attempts in a row. This security feature is on all SIM cards and is designed to prevent unsolicited network and data access. Once it is blocked, users will need to enter an eight digit PUK code to regain access to the network. However, it’s worth noting that emergency calls can still be made when the phone is in this state.

A PUK code is stored electronically inside the SIM and is retrievable by calling your network operator. Sometimes it is included within your initial mobile documentation so it’s worth checking here too, but this is very rare. As an additional security measure, the PUK code is generally unknown to the user and some networks even take the step to offer access to them as a dedicated service. If a PUK code is entered 10 times incorrectly, the SIM must be returned to the operator for reactivation.

PUK1 and PUK2 are used to unblock PIN1 and PIN2 respectively. As PIN1 is the primary means of access to a handset, blocking PIN1 will block the entire handset until PUK1 is entered. Similarly, as PIN2 only manages restriction of a small set of features (restricting certain numbers, access to PIN1 etc.) the blocking of PIN2 will still allow normal operation of all handset functions apart from those that normally need a valid PIN2, which remain locked out until the PUK2 is entered.

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