Unlocked Iphone, does it work in all countries?

I'm considering ordering an iphone 4s off of ebay that's unlocked. It was originally purchased and I believe unlocked in Australia. Does that mean it's "unlocked" in all countries? Or will it only work with all carriers in Australia? Reason I ask is I'm moving to the USA soon, but I need a phone right now while living in australia.

If it is unlocked then you can use it almost anywhere in the world with any SIM card.

If its unlocked then it would work anywhere.

  • Will my Iphone 5 work in other countries? I've got an iphone 5 and my family and I are thinking of going to America for a holiday. I want to use my phone there aswell. Do i have to unlock or get a new sim from America? I'm not quite sure what to do.
  • Will iphone 5 from other countries work in india? IPhone bought in other countries such as UK, USA or any other countries work in India. It may be the unlocked version. What date might it be released?
  • Will an unlocked iphone work in all the countries in the world? Usually when people list 'unlocked' on an iPhone site they mean unlocked for United States countries. If I buy an unlocked iPhone abroad in Europe (or from a European person selling through amazon or ebay), will it still work in the United States on a local carrier?
  • Will an unlocked iphone 4S work for tmobile if it isn't factory unlocked? I want to get an iPhone 4S and my friend has the iPhone 4 unlocked but i'm worried that if i get it non-factory unlocked it won't work. My uncle tried to do it a couple of months ago and apple said that if it was factory unlocked every time the phone shut off or died it would reset. I was just wondering if the same thing would happen if it wasn't factory unlocked? So if I get it unlocked everytime it will shut off it will reset? That is what i'm worried about.