Don't know yet...........
I've had the same phone for going on what, 10-11 years now???
Started with AT&T. After seeing what T-Mobile offered with rate plans, tried to get AT&T to match them. Wouldn't budge, so 8 years ago I switched to T-Mobile and cut my cell phone costs by 60%. If the buy-out surges my cell bill up to AT&T rates again, I'll take "MY" cell phone number elsewhere.