But there are some minor differences between T-Mobile and AT&T that set the two apart. T-Mobile, for example, has a much larger 5G network meaning you're likely to get faster data speeds if you're using your phone in major cities and metro areas.

T-Mobile's Merger With Sprint: Everything That's Changed 3 Years Later. T-Mobile has expanded its 5G network and kept plan and phone prices down, but other premerger pledges are still unfulfilled.