Originally Posted by MSNemitz
First and foremost I'd like to say .... Man, it feels good to be back. I left Android for a few years due to battery issues. I just left VZW and switched from a iPhone 5 to a Note 3 on T-Mobile. My wife has a VZW HTC One (M7) and I was told it would work on TMo, so far we are having no luck getting anything besides Edge. Sorry if already posted but I did look around to try to find an answer. I have spent time talking to VZW, TMo and HTC and no luck. Will rooting give me the ability to fix this?
Verizon phones rarely work on other carriers. Besides the fact that they usually lock the SIM (meaning only VZW SIM cards will work unless you leave the US - ie: "global phone"), different cellular frequency bands are used. Specs on the M7 that I found on phonearena state that the VZW M7 uses 700MHz (band 13), which T-Mobile doesn't use (PA's specs aren't always 100%% though). So even if you could unlock the SIM somehow, you wouldn't get data; not at LTE speeds anyway. LTE radios in phones are actually fairly expensive components, so carriers will often order specific versions from the manufacturers that only support their own bands to keep costs down (and/or profits high).
I think your best bet would be to sell or trade the M7 for a T-Mobile or unlocked one.