PUK is an acronym for Pin Unblocking Key. It is associated directly with your SIM card and the security of the phone
(like setting up a password, etc).
Most commonly, a phone will prompt you for this code when you go through the security settings
and select that you would like to have your phone password protected. The phone will then ask you to enter the PUK code, giving you only a few chances before it will display "PUK blocked". (If you phone says "PUK blocked" right now, call your service provider (AT&T
, T-Mobile, etc) to get a free one and save yourself $25)
The PUK code is not anything you have created. Do not try generic codes like 0000 or 1234. It is an eight digit, factory defaulted series of random numbers.
To get the code and to avoid breaking your SIM card
and having to purchase another, immediately contact your service
provider (AT&T, T-Mobile, etc) and they will give you the code in less than five minutes.