If your SIM is used in a different phone, activation will need the SIM PIN, which is different from your phone’s unlock PIN. To protect against accidental PIN entries, only three incorrect ...

[Jason] already knew what the SIM unlock command would look like ... he was able to work his way backwards and determine the unlock command and its PIN code. It turns out the PIN was even being ...

A PUK code is required if a GSM SIM card was locked after entering the wrong PIN code three times in a row. Entering a wrong PUK code ten times in a row disables the SIM card permanently.