AT&T and Verizon are both taking measures to encourage customers who buy the iPhone 5 to sign up for their new shared data plans. AT&T / September 13, 2012 As pre-orders for Apple's iPhone 5 get set to begin Friday, AT&T and Verizon have both taken measures to get customers to sign up for their new shared data plans. Both U.S. carriers introduced new shared data plans -- called Share Everything for Verizon and Mobile Share for AT&T -- earlier this year, and they've been pushing them on customers since they launched last month. Now new customers who buy the iPhone 5 from Verizon will have to get the company's Shared Everything plan. They don't have a choice. As for existing Verizon customers, they can choose to stay on their current plan or switch to Share Everything. However, if they don't switch they won't get the iPhone 5 at its $199 subsidized price. Neither Apple nor Verizon have announced the iPhone 5's full price, but it could be upwards of $600. Meanwhile, AT&T will sell the phone at its subsidized price regardless of the plan you have as long as you agree to a two-year contract. But AT&T will reserve one of the iPhone's new features only for Mobile Share customers. That feature is cellular FaceTime, which allows users to make video calls on their iPhones over 3G or 4G networks. WiFi FaceTime calls, which have been available since 2010, will still be allowed, but cellular FaceTime will be available only to Mobile Share customers. Sprint and Verizon have no plans to restrict cellular FaceTime calls.