Summary:

- AT&T is offering up to $1,000 off the upcoming iPhone 15 models when customers trade in an eligible device and sign up for a new unlimited plan.
- The promotion is part of AT&T's efforts to attract new customers and encourage upgrades to the latest iPhone models.
- The $1,000 trade-in value is the highest offered by AT&T for the iPhone 15 lineup, making it an attractive option for customers looking to upgrade their devices.