Will an unlocked iPhone work in America?

I have an unlocked iPhone 5 that I currently use with a giffgaff sim in England. I'm going to America in a month and I want to know if my phone will work if I put an American sim inside it? (AT&T or Verizon sim).
I'm asking this because I have seen/heard people say before that there English phone doesn't work once they go to America

Yes it will work in america my friend took his i phone on holiday over there and it worked

Unlocked mobiles can be worked any where inthe world with anysim
you can use it in america without any doubt.

Yes, if unlocked it will work here with either AT&T or T-Mobile. It MAY work with Verizon if it supports LTE. My recommendation would be T-Mobile, AT&T and Verizon are very overpriced.

  • Will an Iphone 5 that i buy in America, work fully in Australia? - 2 So if i buy an Iphone 5 UNLOCKED in America, will it still be fully functional in Australia with any Aussie carrier without jailbreak? Apparently there's different voltages in America then Australia so i wouldnt be able to charge it?
  • Will an iphone 5 from america work in india? I was planning to ask my sister who lives in us to buy me an i phone 5 will it work in india? What is the procedure of unlocking it? Please any body help me who has experience in it. And teel me the loation where it will be unlocked
  • Will a iphone 5 purchased in America work in Australia? Hi If I purchase a iphone 5 in America will it work it Australia with a Australian sim card as on the Apple website it shows some American carriers. If it will be locked it is there a way to get unlocked?
  • Should I buy an Iphone 5s from America and use it outside of America? An Iphone s where I live costs around $600.In America it costs around $199 plus a $70 year contract so it seems more reasonable to order it online from America. If I order it from America what would I need to do and what should I know before ordering an Iphone from America and using it in another country? Besides unlocking the phone, what else do I need to do?