The PUK code for your cell phone is a SIM card-specific code assigned by the service provider. If you have entered an incorrect pin into your phone three times, the SIM card on your phone will lock and you will be unable to use your phone. An error message will appear asking you to "Enter PUK Code." The PUK code is available through your service provider.
Don't try to guess your phone's PUK code. If you enter the wrong code three times, or sometimes five times depending on your phone type, you will end up with a completely locked SIM card that will need to be replaced.
Go to your online cell phone account. Log in with the username and password that are assigned to the account. Some providers include the PUK code along with the rest of your online account information.
Click on the "Phone" or "Device" option on your online account. The name of this section will vary by provider. When you click on this option, you will be taken to a section with information regarding your cell phone.
Look for an option to "Unblock SIM Card" or any other SIM card selection. Once the information regarding your SIM card opens, see if there is an "unblock" link. If your provider does have an "unblock" section, follow the instructions exactly to unblock your SIM card.
Call your provider. If the PUK code could not be found on the online account, you must get it directly from the customer service department of your cell phone provider. Be prepared to answer questions to confirm your identity, such as billing address or email address, and possibly provide them with the number on your SIM card. Once you have given proof of your identity, your provider will give you the PUK number. If possible, enter the PUK code into your cell while you are still on the phone with customer service. This will save you time if the code fails to work.