Though toll-free dialing exists in most parts of the world, according to the telephone website Namada, the format for toll-free numbers varies considerably from area to area. The 1-800 format familiar in the United States and Australia often does not appear in overseas nations; in the Dominican Republic, for example, toll-free numbers begin with "1-200," and Swedish callers prefix toll-free calls with "020."
Many domestic toll-free service providers allow users to exclude area codes or geographic regions from using the toll-free number. According to the toll free number administration organization SMS/800, users typically employ this service to restrict international calls, sometimes including those from other countries on the North American dialing plan like Canada and Mexico.
Although overseas telephone networks frequently use different numbering plans for toll-free numbers, a system is available that could facilitate international toll-free telephone calls. The telephone call set-up system, known as the signaling system, in its seventh revision as of December 2010, serves as a global standard for establishing and facilitating telephone connections.
