List of telephone country codes

Country codes are defined by the International Telecommunication Union (ITU) in ITU-T standards E.123 and E.164.

Country codes constitute the international telephone numbering plan.

Country codes are dialed before the national telephone number, but require at least one additional prefix, the international call prefix which is an exit code from the national numbering plan to the international one.

The nine world zones are generally defined geographically, with exceptions for political and historical alignment.

(but also Aruba, Faroe Islands, Greenland and British Indian Ocean Territory) Some of the larger countries were assigned two-digit codes to compensate for their usually longer domestic numbers.