How to Fix a Blocked PUK

By Eric Wilborn

A PIN code on your SIM card helps protect your phone's data.
i George Doyle & Ciaran Griffin/Stockbyte/Getty Images

For the safety of wireless subscriber's data and monetary investment, many GSM phone manufacturers (such as AT&T and T-Mobile) provide an option to place a PIN lock on a SIM card. This PIN lock keeps strangers from accessing what's on the SIM card or making calls with the locked phone. If you enter an incorrect PIN code three times, a PUK (Pin Unlock Key) code will be requested. This number is provided by the service provider.

Take the battery cover off of the blocked phone and remove the battery.

Write down the phone's IMEI and SIM card number. The IMEI can be found on a sticker behind the phone's battery (which you've already taken out). The SIM card number is printed on one side of your SIM card.

Put the phone back together and power it on.

Call your wireless provider from another phone and ask to speak with someone about PUK unlocking.

Provide the representative with information from the phone and SIM.

Put the given code into the PUK lock screen to unlock your phone and SIM.