PIN for Samsung S3

[AC Question]

I bought a Samsung S3 unblocked brand new in the UK and tested it with my UK SIM card before taking it to my friend in Brazil, it worked normally.
My friend tested the phone in Brazil with a SIM card from somebody else and the screen is asking for a PIN. Is the PIN associated with the SIM card or with the S3 set?
Which PIN is this?
Thanks

 

[Golfdriver97]

The PIN must be associated with the SIM card. Otherwise, it should have been locked when you tried for the UK.