The second phone wasn't free immediately at the point of sale. Instead, the discount was applied as :

: AT&T provided credits totaling up to $999.99 (the retail price of the 64GB at the time).

, but it was designed to lock customers into a multi-year service commitment. If you're looking for current offers, I can help you find: for the latest iPhone models Special bundles including the Apple Watch or iPad Plan requirements for new customer switching promotions

: Both lines had to be on a qualifying postpaid wireless plan, typically an Unlimited Plan .

: If you canceled the service or paid off the device early, the remaining bill credits would stop, and the full remaining balance became due. Model Flexibility

AT&T Offering Buy One, Get One Free Deal for iPhone X | Shacknews

was a major promotion launched in 2018 that allowed customers to receive a second 64GB model for free, or a significant credit toward the 256GB version. Core Offer Requirements