Unlocked phones will work overseas?
I am on a family plan where internet is free in 215 countries. I see a lot of brand new 5G phones on Ebay that are either unlocked or on Simple Mobile or Mint or Metro mobile which all use Tmobile network. Does that mean they will work overseas my with Tmobile plan? What determines workability on overseas with Tmobile plan? Is it the Tmobile software on the phone that makes it work overseas? (Some of these phones dont have TMobile software) Or is it bands/frequency of the phone? I read on other topics that FCC ID is needed to determine if it works on Tmobile? Can someone help?