I've been using an unlocked iPhone 3GS for about a year and a half years in South Korea, under SK Telecom. However, I just moved to the States and I want to use this phone under AT&T. The problem is that when the AT&T store rep placed his SIM card, which he said that it works for any phone voice & data, into my iPhone, an invalid sim warning popped up.
Does this mean that my iPhone is actually locked? (Which seems almost impossible seeing I was able to use this phone on SK Telecom [Verizon of South Korea] when it was originally exclusive to KT [AT&T of South Korea])
I also noticed that there is a carrier update on my phone, which shows SK Telecom 10.1....
Does this mean that my iPhone is actually locked? (Which seems almost impossible seeing I was able to use this phone on SK Telecom [Verizon of South Korea] when it was originally exclusive to KT [AT&T of South Korea])
I also noticed that there is a carrier update on my phone, which shows SK Telecom 10.1....