In some implementations, a computing device may determine a location of the computing device. The computing device may have an associated first phone number. The computing device may determine that the location of the computing device is outside a geographic area in which a carrier associated with the first phone number provides service. The computing device may send a registration request to a local network indicating that the computing device is operating in an over the top mode. The computing device may originate an outgoing call from the computing device. The outgoing call appears to a called party to originate from a second phone number that is different from the first phone number.