We have been asked this question many times by many international iPhone fans, especially from underdeveloped or developing countries, because either iPhone is not available or too expensive to buy where they are from.
The short answer: Most likely yes.
The long answer: The factory unlocked iPhone includes all the features of iPhone without any commitment. The unlocked iPhone 4 requires an active micro-SIM card that you need to obtain from a supported GSM wireless carrier of your choice in your country (e.g. AT&T in the United States). Please note that the unlocked iPhone 4 or iPhone 4S will not work with CDMA-based networks. You should also understand that your warranty & service will only be valid in the U.S. You will not get warranty support in your own country.
Obsessed with tech since the early arrival of A/UX on Apple, Sudz (SK) is responsible for the editorial direction of AppleToolBox. He is based out of Los Angeles, CA.
Sudz specializes in covering all things macOS, having reviewed dozens of OS X and macOS developments over the years.
In a former life, Sudz worked helping Fortune 100 companies with their technology and business transformation aspirations.