Last reviewed: September 2, 2026
International calling codes are telephone routing prefixes used when dialing across national networks. They are separate from ISO country codes: a two-letter code such as JP identifies Japan in many data systems, while an international telephone call uses the calling prefix +81.
Why some countries share a calling code
Telephone numbering plans do not map one-to-one with sovereign states. The North American Numbering Plan, for example, shares the +1 country calling code across multiple countries and territories, with additional area codes distinguishing destinations.
How to use this site’s calling-code field
Country profiles show calling-code information as a quick reference. For an actual international call, verify the complete dialing format with your carrier because trunk prefixes, mobile formatting and local numbering rules can affect the final number.