iPhone 4S CDMA unlock use GSM

[richard99uk]

Hi there, I'm sorry if this has been answered but I've been looking for a while and couldn't find a straight answer to my question. Thanks very much for any help.

I'm using an iPhone 4S with baseband 2.0.12 on a CDMA network in Japan (KDDI/AU). I want to know if it is possible to unlock the phone, so it can be used on a UK GSM network -- either through hardware or software, jailbreaking or not. I read somewhere that getting the phone into GSM mode will mean I will never be able to use CDMA mode again.

I'm going back to the UK in a couple of months and I want to use data, which my Japanese network will charge and and arm and a leg for in the UK.

I would be really grateful if someone could tell me the score, so I know what my options are.

Many thanks again.

[Wilsonium]

I would first try to contact your carrier to get the international roaming unlocked so you can use a local prepaid SIM when you travel to the UK. Failing that, jailbreak your phone and use a Gevey SIM interposer. Seems to work for most folks around here. Visit http://www.applenberry.com/unlock-ve...dma-iphone-4s/ the Gevey SIM interposer and instructions.

[richard99uk]

Thanks very much for the reply! Just one point I'm a little confused about.

I notice that the instructions say it's only for the Verizon iPhone 4S and that if I have another CDMA network I should use instructions on a different page. But that page doesn't mention anything about using a GSM network.

Thanks again!

[Wilsonium]

I believe what they mean is that out of the box the Gevey interposer works for Verizon iP4s. It is changeable tho and there's an included reset SIM that puts the interposer into a learning mode so you can change it. The Gevey interposer only needs to know what network the phone is tied to and since it's a CDMA phone, you'll only see CDMA carriers in the list... You would select Sprint from the list if your iPhone 4s came from sprint. Once your Gevey is reset and knows it's a Sprint iP4s then you should be good to go and use your GSM SIM of choice along with the interposer.

[richard99uk]

Got it. Thanks very much for your help!