Help and information about unlocking iPhone 3GS to use on T-Mobile

[anthonyt123]

Hey everyone, I've visited this site many times and looked around, but I've only just registered and I have a question I hope you can help me with.
I live in the UK and I purchased my iPhone 3GS when it was released but I got it on O2 pay as you go instead of the contract because I didn't really used to use my phone much.
The last 2 or 3 months I've been using my phone alot, and I've been spending alot on top ups but now I want to go on a sim only contract. I was checking out the O2 sim only tariffs but they are terrible, all of O2's contracts are rubbish. I was looking at T-Mobile sim only contracts and I really want to go onto T-Mobile. However seeing as the iPhone is only for use on O2 in the UK, getting onto T-Mobile I understand might have a few problems, including not being able to access 3G which is a major down point.
I've looked at yellowsn0w and would use it, however as I mentioned I don't want to lose access to 3G and I don't want to mess up my basebands my updating my firmware to 3.1, I'm currently on 3.0.1
Any help or advice would be greatly appreciated, and if I'm wrong about accessing 3G could somebody please correct me. Thanks for your time

 

[dazey]

My work phone is currently my old 3g jalibroken and unlocked using ultrasnow (yellowsn0w successor) and used on T-mobile. Obviously you don't get visual voicemail but 3g works just fine as soon as you put the right APN settings in.

 

[sparrky]

3g works just fine as soon as you put the right APN settings in.

Do those APN settings only work for the UK T-Mobile? Because as far as I know, there's no way for US T-Mobile iPhone users to use 3G.

anthonyt123, I think 3.01 is the latest firmware as of right now, so you don't have to worry about messing up your baseband. I haven't upgraded to 3.01 yet (waiting for saurik's method), but I do know that it's able to be jailbroken/unlocked.

 

[superflush]

However seeing as the iPhone is only for use on O2 in the UK, getting onto T-Mobile I understand might have a few problems, including not being able to access 3G which is a major down point.

I would think that you would be able to use T-Mo 3G, but I'm not basing that on anything.

You may want to take a look at this: http://www.engadget.com/2009/08/04/t-mobile-uk-sneakily-offering-iphone-3g-to-moneyed-customers/
If T-Mobile UK itself is giving iPhones to customers, I'm guessing the 3G can work.

I looked in Cydia for any T-Mobile UK packages, but didn't see any (There are T-Mobile US packages for 'carrier support' in Cydia).

You may just be able to manually change the internet settings to get it to work.

 

[dazey]

Do those APN settings only work for the UK T-Mobile? Because as far as I know, there's no way for US T-Mobile iPhone users to use 3G.

I think that this is something to do with some of the US carriers using a different type of 3G. Does not apply in the uk.