AT&T Wireless: Buy One Eligible iPhone, Get an iPhone XR Free + $300 Gift Card

You'll need to:

Purchase two eligible iPhones on AT&T Next or AT&T Next Every Year installment agreements
Add at least one new line to a new or existing account
Pay taxes on the full retail price of both devices up front.
Have an eligible wireless plan (min. $100/mo. combined before discounts for new customers. Existing customers can add to eligible existing plans).
Pay a $30 activation or upgrade fee for each device