A system and method for registering the contact information of mobile devices with a service 911 service is presented. In one embodiment, a mobile switching center receives the contact information of a mobile device. If the mobile switching center determines that the mobile device is not located within a particular wireless sub-network, such as, but not limited to, a wireless sub-network associated with an area code registered to the mobile device, the mobile switching center generates a reverse 911 registration text message and transmits the reverse 911 registration text message to the mobile device. A user of the mobile device may then transmit the reverse 911 registration text message to a local reverse 911 database to have the contact information associated with the mobile device added to the local reverse 911 database.