> An unlocked mobile device cannot be locked to a carrier because the SIM lock mechanism is disabled If it's a Best Buy "unlocked" iPhone it can! It was unlock

> An unlocked mobile device cannot be locked to a carrier because the SIM lock mechanism is disabled If it's a Best Buy "unlocked" iPhone it can! It was unlocked when he bought it, but locked onto the first network it was activated (Fi is T-Mobile[1] MVNO) 1. and AT&T too for fully supported Fi phones - you can get seamlessly handed over between T-Mobile, AT&T and wifi. However, iPhone are not fully supported, so they exclusively use T-Mobile.