Well subsidy unlocks are really a different thing to PUKs. Carriers won't let them out usually until you've completed a contract or ToS in full. They can have subsidy locks on carrier supplied phones in UK as well. And the only time I've ever had to deal with that was when i bought the first iPhone from O2, as prepaid back in 2008. It was only £180, as opposed to the £400-500 Apple was asking for an unlocked non-carrier iPhone. I had no intention of using it with the included O2 SIM. Fortunately in them days the subsidy lock was easy to deal with just by jailbreaking the iPhone using YellowSn0w. Phones here in China are always unlocked.The only 'scratch off card' that comes with a US SIM card is the SIM card number itself. PUKs are supposed to be carrier provided but as stated, here, they protect it like a government secret. They make claims that you should never see the request for a PUK, PIN2 or Subsidy Unlock unless YOU are doing something nefarious.