A method of and system for optimizing interactive voice response (IVR) unit port utilization starts each call of a plurality of calls on a separate IVR unit port. The method launches an IVR call flow for each call. Each IVR call flow includes a section that is common to all of the call flows. The method conferences together on a single IVR unit port at least some of the plurality of calls for the common section of the call flow by transferring calls to the single IVR unit port when each transferred call reaches the common section. The method synchronizes the calls conferenced together on the single port by inserting into the call flow on the single IVR unit port an on-hold treatment. The method starts the common section of the call flow when all calls have been transferred to the single IVR unit port.