ISO 4217

By Laurent · Aug 2026

The international standard defining three-letter currency codes used in banking, commerce, and forex trading. ISO 4217 codes like USD, EUR, and GBP are the universal language for identifying currencies worldwide.

What ISO 4217 Defines

ISO 4217 is maintained by the International Organization for Standardization and assigns three-letter alphabetic codes and three-digit numeric codes to each currency. The first two letters typically represent the country (from the ISO 3166 country code), and the third letter usually represents the currency name. For example, USD = US (United States) + D (Dollar), GBP = GB (Great Britain) + P (Pound).

ISO 4217 in Forex

Every forex currency pair uses ISO 4217 codes. EUR/USD, GBP/JPY, and AUD/CAD are all constructed from these standard codes. The system eliminates ambiguity: "dollar" could refer to multiple currencies, but USD, AUD, CAD, NZD, SGD, and HKD each identify a specific one.

The standard also assigns codes to precious metals (XAU for gold, XAG for silver) and to supranational currencies. Special codes beginning with X are reserved for non-country currencies and testing purposes (like XDR for IMF Special Drawing Rights).

Key fact: When the Euro (EUR) was introduced in 1999, it received the code EUR (not following the country-code convention since it spans multiple nations). It replaced codes like DEM (Deutsche Mark), FRF (French Franc), and ITL (Italian Lira).

Practical Use

All forex trading platforms, bank transfers, and financial data services use ISO 4217 codes. Traders rarely think about the standard consciously, but it underpins every quote, transaction, and analysis in the forex market.