This year, Apple is selling a contract free iPhone 6 from day 1 of its launch in the US. This contract free iPhone comes bundled with a T mobile sim card which is creating a lot of confusion about whether the phone will be locked to the T mobile network. Apple support executives are further adding to the confusion by saying that only T mobile customer care can confirm this. And T mobile reps say that one has to get unlock codes from them to unlock the any phone on their network, however, they are not 100% sure about the iPhone 6.
I bought a contract free T mobile iPhone 6 on launch day and have tested it on Straighttalk wireless in the US. Well, technically its the AT&T network as I have an AT&T compatible sim from Straighttalk. The contract free (T mobile) iPhone 6 works perfectly fine out of the box on the AT&T network. So if you are looking for a factory unlocked iPhone 6, go for the contract free T mobile version from the Apple online store or the Apple retail store. We are still not sure if the contract free ones being sold at the T mobile stores are unlocked or not. They should ideally be unlocked too, given that you are paying full non-subsidized price for them. However, to be safer, if you want an unlocked iPhone 6, get the contract free T mobile version from the Apple online store or the Apple retain store.