Toll-free numbers are telephone numbers with distinct codes that can be dialed from landlines and, in some countries, from mobiles with no charge to the person placing the call. Such numbers allow callers to reach businesses and/or individuals without being charged a long-distance or international fee for the call.

The majority of use cases for toll-free numbers are customer service calling related. Usually, toll-free numbers are assigned to a call center where agents handle incoming customer calls. Outbound calling using toll-free numbers is rare and is not supported in some countries. Outbound calls with toll-free numbers can be filtered, blocked or not properly routed to its destination by terminating carriers. In some cases, such calls can be terminated at a higher than expected rate.