Carrier AT&T IUP iPhone on T-Mobile?

[welles13]

I mean, this configuration should work, right? Taking an ATT phone on the Apple Upgrade Program that you bought online from Apple - because T-Mo for whatever reason demands you go into the store - and immediately inserting your own T-Mo SIM. It's unlocked, right?! I'm just slightly concerned with the 'connected to AT&T' label here...

 

[justinf77]

That's what I plan on doing and I assume it will work fine. The phone comes 100% unlocked, I don't see there being a problem.

 

[Dirtydutch]

It'll work they're both strictly GSM

 

[James.K.Polk]

Did this work? It's my understand you need to enter your ATT account info to proceed.