IVR systems are used to service high call volumes at lower cost. The use of IVR allows callers' queries to be resolved without a live agent. If callers do not find the information they need, the calls may be transferred to a live agent. The approach allows live agents to have more time to deal with complex interactions. When an IVR system answers multiple phone numbers, the use of DNIS ensures that the correct application and language is executed. A single large IVR system can handle calls for thousands of applications, each with its own phone numbers and script.