Your question is misleading because you literally unlock a SIM-enabled phone, like those manufactured and distributed by Nokia, by entering the PUK code on the screen. PUK stands for PIN Unlock Key.
Now, if you are prompted to enter the PUK it is probably because your mobile device has a special security feature that protects the SIM card; or rather protects the personal information that is stored on the SIM card. When the security feature is active, you are required to enter the SIM PIN in order to use the device.
Much like the way entering the wrong password at your online banking interface might lock you out of the system, entering the wrong PIN on your SIM card will also lock you out. If this occurs you will need to obtain the PUK in order to use the phone. Sometimes, when you transfer the SIM card to another phone, you may also be prompted to enter the code.
You probably don’t have this code just lying around so you will have to contact your wireless service provider in order to get the phone. Most companies has a toll-free number and 24-hour customer care services so you should be able to do this at your convenience, which you can find either on their website or even on your bill. Call the number and verify your identity and they will give you the code. Then enter the code on the keypad or touch screen on your phone and you will unlock the SIM card.
Now, if you are prompted to enter the PUK it is probably because your mobile device has a special security feature that protects the SIM card; or rather protects the personal information that is stored on the SIM card. When the security feature is active, you are required to enter the SIM PIN in order to use the device.
Much like the way entering the wrong password at your online banking interface might lock you out of the system, entering the wrong PIN on your SIM card will also lock you out. If this occurs you will need to obtain the PUK in order to use the phone. Sometimes, when you transfer the SIM card to another phone, you may also be prompted to enter the code.
You probably don’t have this code just lying around so you will have to contact your wireless service provider in order to get the phone. Most companies has a toll-free number and 24-hour customer care services so you should be able to do this at your convenience, which you can find either on their website or even on your bill. Call the number and verify your identity and they will give you the code. Then enter the code on the keypad or touch screen on your phone and you will unlock the SIM card.