Systems and methods for determining the geographic location of a user based on limited and ambiguous information available from the user's mobile electronic communication device are provided. In an embodiment, a computer-based system estimates a device's physical location based on partial identification information collected from the device such as the local area code and cell identification number, and numerous non-locational attributes. When the system determines that the collected information from the device corresponds to more than one single geographic location the system may use additional techniques of iterative disambiguation and filtering to determine a predicted location. Additional techniques may be used to increase the confidence level of the predicted location.