ISO 4217 is the international standard describing three-letter codes ( also known as the currency code ) to define the names of currencies , as established by the International Organization for Standardization ( ISO ) . The ISO 4217 code list is the common way in banking and business , all over the world , for defining different currencies . The table below shows the ISO currency codes of former currencies and their common names ( which do not always match the ISO 4217 name ) .