Pure Talk uses T-Mobile. We have Pure Talk and haven’t had service since I woke up this morning. Phone displays “SOS”.
“PureTalk” = AT&T cell network.
https://bestmvno.com/compare/att-mvnos/
https://bestmvno.com/mvnos/pure-talkusa/#google_vignette
https://www.whistleout.com/CellPhones/Reviews/puretalk-review