It will send a text to let you know when the iPhone is unlocked. You then just need to pop in the new SIM card and it should show as unlocked. If you’ve been with Tesco Mobile for 12 months or ...
A four-digit SIM PIN restricts unauthorized access to the SIM card ... and iPhone. As previously mentioned, three incorrect PIN attempts will lock your SIM, requiring a PUK to unlock it.
However, iPhones were readily "unlocked" by hackers both in and ... prohibited or a recipe for marketing failure. See SIM card and iPhone jailbreaking. THIS DEFINITION IS FOR PERSONAL USE ONLY.