AT&T Mobility LLC is the wholly-owned wireless subsidiary of AT&T. It is headquartered in Atlanta, Georgia,[2] AT&T Mobility currently serves over 87.0 million subscribers.[3] This makes it the second largest wireless telecommunications provider in the United States, based on number of subscribers, behind Verizon Wireless. AT&T had been the largest before Verizon Wireless completed the acquisition of 32 of 56 markets of Alltel Wireless in early 2009. Total wireless revenues for 2008 were $49.335 billion, up $6.7 billion or 15.6 percent versus 2007 results. Additionally, AT&T Wireless is the largest wireless carrier by revenue.

Among the services that AT&T aggressively promotes is its Rollover Minutes service which allows customers to keep unused minutes from month to month on a twelve-month rolling cycle on its popular Nation nationwide plans. Beginning in July 2007, AT&T allows its AT&T Unity plan users to have Rollover, a service which was exclusive to the Nation plans. AT&T also launched video share in 2007, in which a mobile caller can stream live video from one phone to another over the 3G network with video share capable phones. This allows one mobile phone user to view video from another users camera through the mobile phone in real time. AT&T rolled out a program on September 20, 2009, called the A-List, similar to Alltels My Circle (which was later adopted by Verizon Wireless and renamed Friends & Family). Customers with individual Nation plans of $59.99 or higher can use A-List with Rollover to select up to five domestic phone numbers to call anytime --including landlines and wireless numbers on any network-- without using any of the minutes in their plan. FamilyTalk customers with plans of $89.99 or more can select up to ten numbers which any person in the FamilyTalk plan can call as much as they want.