Unlocking iPhone 4 Question

[marcel37]

Hi everyone,

Here is my situation:

I have just bought a used AT&T iPhone 4 from a friend (Latest iOS - I think. the phone was reset and I do not have a SIM Card in order to activate it, check baseband, and start working). I want to unlock it. Jailbreaking doesn't necessarily interest me.

My problem:

I want to use it as a prepaid phone in the US and on foreign carriers in countries where I work and travel. However, there is so much information about this on the net that it is hard to tell what is the most recent solution.

I don't know about redsn0w, ultrasn0w, the Gevey Sim card, cutting an ATT sim card to fit the iPhone 4 tray so that I can at least use it in the states as prepaid... etc. All of this just kind of lands on me in one big mass of information when googling the topic.

I don't know where to start or whether I should just take it to some guy who will unlock it in his shop for 25$.

My plea:

Can anyone share with me what they did to unlock their 4's and the problems they encountered? Give me some advice as to where to start this process and, hopefully, streamline it?

Any advice appreciated,

M

 

[Applejuiced]

If its on the latest iOS 5.0.1 it cannot be unlocked with anything at the moment.
It will only accept AT&T sims since that's the carrier its locked to. You can also use prepaid AT&T sims in the US and many other AT&T based prepaid carriers like H2O for example.

 

[marcel37]

How can I downgrade to an older iOS?

What about this: http://www.ziphone.org/?

If an unlock for 5.0.1. is not attainable at the moment, what would be the best way to activate it on AT&T? They said I cannot use iPhone 4 as a prepaid phone.

 

[Applejuiced]

How can I downgrade to an older iOS?

What about this: http://www.ziphone.org/

Only with shsh blobs, but even if you do you cannot downgrade the baseband that does the unlocking. Once a baseband on the i4 is updated it cannot go down.
I told you above, there is no way to unlock an iphone 4 on 5.0 or 5.0.1
If you were on 4.3.5 or below you could have used gevey.