Unlocking iPhone - question on SIMs and country

[jent]

I'm on AT&T and have a question regarding family members' phones that have just received unlock approvals from AT&T.

My family members bought their phones from AT&T, so they are locked to that carrier. Since the unlocks have been approved, I know I can just pop in a different SIM to finalize the unlock.

If I'm not mistaken, this can be any SIM card, even if it's not active or from a different country, right? I have inactive ones from U.S. and foreign carriers alike that would be easy to use. I have active ones on Sprint but that's a little harder, as I have to contact Sprint to program the SIM's ICCID to the phone's IMEI.

How can I know when the unlock has worked if using an old and inactive SIM? Does the carrier name text in the top left read "No Service" instead of "Invalid SIM"?

Lastly, does this have to be done in the U.S. to work? Or if they travel abroad, buy a local SIM, and then insert it into the phone, will that also work? I'm not sure if one has to be in AT&T coverage territory to finalize the unlock on an AT&T phone, for example.

Thanks for your help!

 

[Givmeabrek]

If they are unlocked they are unlocked.
No need to finalize.
Enjoy.

 

[Applejuiced]

Correct, if they are unlocked they will activate with any sim.
Even if the sims are inactive. Stay away from Sprint sims since they are a CDMA network and more complicated than all other carriers when it comes to unlocked phones getting access on their network.
The phone will bring you to the activation screen and if you're connected to wifi it will activate with that sim but display no service on the top left of the phone. It will not say invalid sim.
You dont have to do it at and there is no finalizing the unlock step. Its just to test it out and verify it for yourself. Once the phone is unlocked you insert and use any carriers sim anywhere you are.