Sprint customers can upgrade iPhone anytime, included in monthly rate Sprint (S) announced that customers can upgrade their Apple (AAPL) iPhone anytime, included in their monthly rate. New and upgrade eligible Sprint customers can get iPhone for just $22 per month with iPhone Forever. Anytime customers don't have the latest iPhone, they are eligible to upgrade. They bring their iPhone, upgrade on the spot and away they go. It's that simple. iPhone Forever is available on any eligible Sprint rate plan and upgrade eligibility is always included in your price. New or existing customers who are upgrade eligible can bring in any smartphone and get a 16GB iPhone 6 model and their monthly rate will be reduced to just $15 until their next upgrade. As a special promotion, customers who get iPhone 6 and upgrade before December 31 continue with the discount price of $15 until their next upgrade.