IDT keeps international phone calls cheap, whether you're calling Argentina or Zambia. The communications holding company operates primarily through subsidiary IDT Telecom, which provides prepaid and rechargeable international calling cards and other payment services to customers across the world through the Boss Revolution brand. As a pioneer in international callback technology (sometimes known as call reorigination), IDT Telecom also offers wholesale termination services to reroute international calls through less expensive US exchanges, and payment services including mobile top-up. In addition, the company offers local and long distance services in 11 states under the IDT America brand.