Systems and methods are described for implementing an emergency services address management system for mobile devices. A mobile device may implement “voice over Wi-Fi” or otherwise communicate via wireless networks that do not provide address or location data. An emergency services address management system may associate E911 addresses with individual access points of the wireless networks, and may provide the associated E911 address instead of a default E911 address (which may be a home or billing address that is relatively distant from the user's current location) when a user of the mobile device makes a voice call to an emergency service. The system may identify access points for which an E911 address is not known, and may obtain or generate an E911 address using information from various sources, including the user, satellite-based or cellular-based location services, or other mobile devices that have accessed the wireless network via the access point.