Starting this Spring, Verizon will lock their unlocked phone for some time
Unlike India my home country, United States have carriers who sell mobiles based on their network. Usually, if you buy a device from one carrier and then want to shift to another carrier then you have to pass a cooling period. Known as “Locking”, carriers like AT&T and Sprint set up a time limit on the device before you can use with another carrier’s network. It can take time from 15 to 60 days.
Till now, you can just buy an unlocked phone from Verizon and shift to another carrier immediately. However, they say that it makes easier for the thieves to steal the devices and sell them back on the black market. Therefore, once the new rules get set in the spring, you will need to wait for some time in between 15 to 60 days before you can switch to another carrier after buying unlocked devices from Verizon.