As long as you can get a US address to signup for the account you are good to go, plus you'll need an SSN as they'll run a credit check on you. In the worst case you'll be asked to pay a $500 deposit to enable the line. You will not be able to signup with your non-US address and I certainly wouldn't mention to them that you plan to use it outside the country most of the time, their unlimited intl. plan is meant for people that go abroad every now and then, not for those that live abroad.