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iPhone 4 unlocking help required- unsure about baseband compatibilty


New Member
Jun 18, 2011
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My wife and I both have jailbroken AT&T iPhone 4s.
Mine is running iOS 4.1, modem firmware 02.10.04
My wife's is running iOS 4.2.1, modem firmware 03.10.01
I jailbroke them both using greenpois0n.

We are travelling to the UK for a few weeks this summer and would like to use our iPhone 4s there. We used to live there and still have accounts and SIM cards with one of the UK networks O2.

I'm slightly nervous at attempting to unlock the phones in case all doesn't go according to plan and things don't work the way they should.
From what I've discovered, it looks like ultrasn0w is the tool to use.
But looking at it in the Cydia store it says it's compatible with iPhone 4 baseband 01.59.00 (and other basebands for iPhone 3G/3GS).

Will this work on both our phones with their current configuration?
Or do I need to upgrade both phones to iOS 4.3.3, re-jailbreak (greenp0ison?) and then unlock (will I then have 01.59.00)

Hoping someone out there can help me.
Many thanks


Staff member
Jun 15, 2010
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United Kingdom
jailbreak is not unlock... you can jailbreak any firmware atm but the baseband you and your wife have are not compatible with the basebands you have. so you would need to use gevey sim or a turbo sim like solution to unlock the phone to any network....

jailbreak to you is no good for what you need because ultrasn0w is the unlock app you need to use after jailbreaking but dont try and find it or use it because it does not work and you will just mess up your phone if you try use it... america provides unlocked iphone 4s now maybe you could contact them and ask them to swap your locked to AT&T device for a unlocked one, probably at a small fee but worth it so you can use any micro sim world wide imo then having to rely on these turbo sims.. very un reliable method


Well-Known Member
Feb 6, 2011
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Yeah both of your devices can be jailbreak but none of them can be unlock at the moment using ultrasnow since you are not on the right baseband. I would suggest like Unleashed.

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