Activate iPhone + Still use AT&T?

[britboyj]

I'm going to the UK in June and already have a jailbroken 3G, I didn't select "activate my iPhone" because I'm already on AT&T.

When I'm over there, I can get a Pay-as-you-go SIM and can use it with any phone, in theory.

Can I re-jailbreak, click "Activate my iPhone" and have it work with my AT&T SIM (ie does that option make the phone simply not care what network it's on?) until I go over there?

Once over there, can I just pop the new SIM in and have the phone detect, search and such, or will I have to re-jailbreak with the new SIM already in there?

Supposing both of the above is as easy as I'd like it to be, when I get back can I just shove my AT&T SIM back in, and be good to go?

 

[bytethese]

I'm going to the UK in June and already have a jailbroken 3G, I didn't select "activate my iPhone" because I'm already on AT&T.

When I'm over there, I can get a Pay-as-you-go SIM and can use it with any phone, in theory.

Can I re-jailbreak, click "Activate my iPhone" and have it work with my AT&T SIM (ie does that option make the phone simply not care what network it's on?) until I go over there?

Once over there, can I just pop the new SIM in and have the phone detect, search and such, or will I have to re-jailbreak with the new SIM already in there?

Supposing both of the above is as easy as I'd like it to be, when I get back can I just shove my AT&T SIM back in, and be good to go?

No, you need to unlock your phone first. If your iPhone's baseband is 2.28 you are fine and can use yellowsn0w to do this. If your baseband is not 2.28, you can't unlock your phone.

 

[Vandam500]

No, you need to unlock your phone first. If your iPhone's baseband is 2.28 you are fine and can use yellowsn0w to do this. If your baseband is not 2.28, you can't unlock your phone.

You can now downgrade your baseband. Search for it in Cydia.

 

[DannyBres]

If you have the correct baseband and yellowsn0w installed just pop the new sim in and you should be fine

 

[bytethese]

You can now downgrade your baseband. Search for it in Cydia.

Unfortunately this process only works for certain boot loader versions. Search for it on Macrumors.