Only the account owner, Retail Authorized User, or authenticated caller can transfer an upgrade.
The transferring and receiving lines must be the same type of device like a phone for phone, tablet for tablet.
Swap installment plan or contract terms
When you transfer upgrade eligibility to another line, the transferring line assumes the installment plan or contract terms remaining on the receiving line.
Transfer upgrade eligibility with an AT&T Next smartphone
If the transferring line that is eligible to upgrade has any AT&T Next smartphone installment plan payments, they’ll need to trade in a smartphone of the same make and model. The smartphone must be fully functional, and in good physical condition. Learn more about trade-in requirements.