A request to establish a voice communications session between a user of a telephonic device and an interactive voice response (IVR) system of a call handling system is received by a dynamic call control engine. A resource requirement for the voice communications session is determined. Resource usage data for multiple call handling systems is accessed by the dynamic call control engine. A particular call handling system from among the multiple call handling systems is selected based on the resource usage data and the resource requirement. A connection to be set up between the telephonic device and the particular call handling system to allow the user of the telephonic device to participate in the voice communications session with an IVR system of the particular call handling system is enabled.