US Patent 11172002 System and method for preventing robocall voicemail deposit

Systems and methods for preventing a robocall from leaving a voicemail are described. When an incoming call without a history information header (HIH) destined for a subscriber is detected, the incoming call is prevented from leaving a voicemail if the subscriber does not answer the incoming call. If the incoming call has the HIH, additional determination process based on a visited network address of the subscriber is performed to determine whether the incoming call is to be prevented from leaving a voicemail.