What is a fully unlocked phone?Updated 2 years ago

An unlocked smartphone is a phone that isn't tied to a specific carrier or contract. Therefore, you have the freedom to shop for the latest phones and plans as often — or as infrequently — as you like. Plus, they don't come preloaded with numerous carrier applications that take up space on your phone. And when it comes to international travel, unlocked phones can't be beat.

Unlocked phone network compatibility: 

It's important to pay attention to network compatibility when choosing an unlocked phone. All unlocked phones work on major US carriers. You can choose almost any carrier or plan and all you need is a SIM card. Common US carriers include Verizon, Sprint, AT&T, T-Mobile, Cricket Wireless, MetroPCS, Simple Mobile, Mint Mobile, Tracfone, Total Wireless, and Boost Mobile.