Systems and methods for terminating telephony communications to a mobile telephony device that is roaming outside of its native service area make use of a mobile roaming termination service. The mobile roaming termination service causes the native mobile telephony service provider that provides service to the mobile telephony device to forward incoming telephony communications directed the native telephone number of the mobile telephony device to a forwarding access number. The mobile roaming termination service receives telephony communications directed to the forwarding access number, and then terminates the telephony communication to the mobile telephony device via any one of multiple different methods. The mobile telephony service provider can be instructed to implement and cancel call forwarding instructions by dialing a special character string on the mobile telephony device.