Locate most AT&T phones indoors or out on the AT&T Network!
AT&T FamilyMap uses a number of techniques to determine a phone's location. AT&T phones that have A-GPS (Assisted GPS) return the most accurate locations when they have a clear line of sight to GPS satellites. For example, the phone is outside or is in a car near a window. For phones where A-GPS is not available, FamilyMap uses cell tower information to provide the most accurate location possible, which is usually within a few hundred yards to a few miles of the phone's actual location. This includes non A-GPS phones, as well as A-GPS phones that are not in a clear line of sight to GPS satellites.
Note: Prepaid and Go Phone services are not supported. You may experience issues with FamilyMap being able to locate the Xperia™ Ion by Sony (LT28at). This does not affect your ability to use the FamilyMap app on these devices to locate other phones on your FamilyMap account. We are working quickly to fully support this device.