What is the name of the international standard for country codes used in trade? The standard is ISO 3166.
Published by the International Organization for Standardization, ISO 3166 provides codes for countries, dependent territories and other areas of geographical interest. Businesses, customs systems and international databases use these codes to identify locations consistently when exchanging goods and information.
The standard has three main parts. ISO 3166-1 assigns country and territory codes in two-letter alpha-2, three-letter alpha-3 and three-digit numeric forms. ISO 3166-2 covers principal subdivisions such as states, provinces and regions, while ISO 3166-3 records codes for country names removed from the active list.
The first edition appeared in 1974 with alphabetic codes; numeric codes were added in 1981. The familiar two-letter codes also underpin many internet country-code top-level domains, although domain registries do not always follow ISO usage perfectly. ISO 3166 is not the same as ISO 4217, which identifies currencies, or ISO 8601, which standardizes date and time representations.