My son is moving out to start his first job/career. We were looking into transferring his line to him from my plan so he could take financial responsibility and control his plan. We got him a "free" phone in 2021 with a trade-in device promo credit. Every month my bill shows a payment due of $26 and then immediately following it lists the promo credit for $26. 21 out of the 30 months have passed - so 9 months left. If we transfer the line to him now, it seems like I could pay the $230+ remaining on the cost of the phone or with the proper credit check, he could take over the remaining monthly payments for the phone. But if he did the latter, would the promo credit transfer as well?