I ask this out of genuine curiosity - I’m not sure what happens in the US either, I don’t believe they brick carrier-locked phones that a customer stops paying for but I’m not sure. But I’ve enough experiences with enough people to know this is probably actually a fairly common scenario and I wonder what the consequences are. (A surprising amount of the time, there are no real consequences.)
A phone contract is on one's credit report. If they don't pay, the phone company will try to recover the debt like any other debt (via nagging, and then selling the debt to a collection agency). It's not fundamentally different from not paying the bill at the end of the month.
