Will I be able to use my Japanese Iphone in Australia?

I have a Japanese Iphone and I assumed I would be able to use it in Australia but the person I spoke to on the phone at the phone company said he'd heard that you can't use them in Australia. This didn't seem particularly reliable to me and I was just hoping to get some more reliable information. Surely if it's unlocked, you can use it anywhere?
(I'm talking about moving to Australia and using an Australian provider, not global roaming.)

 

Hi there, now that's a good question, what you need to find out for me is how many bands your iPhone runs on, and whether its UMTS or GSM compatible, or both.

 

How do I figure that out?

 

I do know that it works in Australia on global roaming but I've heard that Softbank (the provider) don't unlock or some such.

 

It should be on the sticker on the back of the phone (where you insert the sim card etc. Or perhaps ask your ISP, what you need it to have is UMTS capability GSM AND UMTS would be better and it needs to be at least tri band preferably quad band. While your there, ask your provider if you put another sim card in it will it work.

Also what version of iPhone do you have, 1, 2, 3, 4?

 

I talked to some friends and apparently I can use it as long as I get it unlocked. Now to figure that out...

 

To get it unlocked you've gotta talk to your provider ... it'll cost you a small fee ...

 

I have learned from experience to just call your phone company and make sure 100% that you can do whatever you are trying to do and that it won't cost you money. They have a sneaky way of telling you half truths then sticking you with $400 phone bills at the end of the month for "data roaming fees".