Can I use an unlocked T-Mobile Galaxy S5 on AT&T?
Okay, here's what I can gather...


There should be no real loss of capability if you move to AT&amp;T. While AT&amp;T does not advertise LTE Band 8 capability on its S5s, Band 8 is largely used in South Korea, Japan, and Taiwan; unless you travel to those places, it shouldn't be a problem. I would, however, check AT&amp;T's coverage map to be certain.
T-Mobile allows customers to unlock phones provided certain conditions are met. Click here for more information.


Also, "Quad Band GSM" on T-Mobile is 850/900/1800/1900 MHz, same as AT&amp;T