PUK or 'Personal Unlocking Key' or 'Pin Unlock Key' is a security feature on most mobile devices that protects your SIM card data. A PUK code is required when a SIM Card Pin Code has been entered '3x' incorrectly.
Please note: Unblocking a SIM card with a PUK differs from 'Network Unlocking' which allows a mobile device to be used with other mobile networks.
If you enter the wrong PUK code '10 times in a row', your SIM card will be invalidated, and will display an error message:Â PUK blocked call operator. If you see this error, you will need to purchase a new SIM Card.