So I have a Samsung Galaxy S-4. When I purchased the phone, they asked me which carrier I wanted to use. I chose Sprint. Well now, I would like to switch to T-mobile. But T-mobile is saying I can do that because they use GSM and Sprint uses CDMA. So here is my question, if I had an option in the beginning to choose from Tmobile or Sprint (GSM or CDMA) why don't I now? My Galaxy allows for a sim card, so why won't it work when I insert a T-mobile sim card into the phone?
Read more: Why can I switch my phone from Sprint to T-mobile?