How to identify factory unlocked iPhone 4?

[MaxBurn]

Found a guy on craigslist selling factory unlocked iPhone 4, how can I identify it from the US locked version?

Will the box marking say unlocked or simply not mention AT&T? Or for all carriers? Would some setting in the phone identify it as unlocked? Something like the imei would be visible and editable?

I don't currently have a tmobile sim or anything to test with.

 

[Nukauk]

You need to ask him for a partition number, which can be found on the box and then check over the internet. For different countries they have different numbers, so be careful))) example can be: mc603b/a. This one is for uk and means that iphone is factory unlocked

 

[CZK]

You need to ask him for a partition number, which can be found on the box and then check over the internet. For different countries they have different numbers, so be careful))) example can be: mc603b/a. This one is for uk and means that iphone is factory unlocked

In canada this method is impossible. Locked phones has the same numbers as locked phones.

 

[MaxBurn]

Ah that would suck about the Canada numbers being the same. The guy would likely be selling a Canadian phone as he is close to the border. I have often thought of taking a trip up there myself to do this, five long hours one way though. Maybe I will organize a group buy

 

[Nukauk]

Sorry, didn't now this

 

[tiartrop]

This looks useful: http://www.cyber-gsm.com/2010/09/how-to-tell-if-your-iphone-4-is-unlocked/

From my understanding though, in a place where there's no official carrier like AT&T, you can get the phone unlocked.

Anyway, I'm sure you can tell apart US iPhone with international one quite easily, i.e. different box labeling and slightly different contents. For one, the AT&T logo shouldn't be there.