The term 'transnational currency' refers to a type of currency that is used in multiple countries. The most common example of this is the Euro, which is used in 19 of the 28 member states of the European Union. The Euro was introduced in 1999 and is the official currency of the Eurozone. It is also used in some non-EU countries, such as Montenegro, Kosovo, and Andorra. The Euro is the second-most traded currency in the world after the US Dollar.