The Eurozone, officially called the euro area, is a monetary union of 19 of the 28 European Union (EU) member states which have adopted the euro (€) as their common currency and sole legal tender. The monetary authority of the eurozone is the Eurosystem. The euro is the second largest and second most traded currency in the global foreign exchange market after the United States dollar.
The Eurozone consists of Austria, Belgium, Cyprus, Estonia, Finland, France, Germany, Greece, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Portugal, Slovakia, Slovenia, and Spain. Other EU states (except for Denmark and the United Kingdom) are obliged to join once they meet the criteria to do so.
No state has left, and there are no provisions to do so or to be expelled.
Andorra, Monaco, San Marino, and Vatican City have formal agreements with the EU to use the euro as their official currency and issue their own coins, and Kosovo and Montenegro have adopted the euro unilaterally, but these countries do not officially form part of the Eurozone and do not have representation in the European Central Bank (ECB) or in the Eurogroup.
Will any Member State leave the Eurozone before 2025?
This question will resolve as Yes if, on or before January 1, 2025, any full Member State of the Eurozone (as of February 10, 2019) ceases to use the Euro as its official currency.
The list of Eurozone member states recognized for this question is: Austria, Belgium, Cyprus, Estonia, Finland, France, Germany, Greece, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Portugal, Slovakia, Slovenia, and Spain.
Note that this question does not apply to Andorra, Monaco, San Marino, Vatican City, Kosovo, Montenegro, or any states that come to be Eurozone members after February 10, 2019; only those expressly listed in the paragraph above. This question also does not apply to the overseas territories of countries which have agreements to use the euro (Akrotiri and Dhekelia, Saint Pierre and Miquelon, the French Southern and Antarctic Lands, and Saint-Barthélemy.)
Resolution is by citation of a press release from the Government or Central Bank of any of the relevant countries, or by credible media reports in the financial press, to the effect that the relevant country actually starts the process of phasing out the Euro as its official currency before 2025, and replacing it with either an existing currency (including but not limited to the US dollar, British pound, Japanese Yen and other reserve currencies extant as of 2019) or introducing (or re-introducing) a national currency of its own. A decision to temporarily leave the Eurozone for a fixed period or until certain conditions are met shall also suffice for a positive resolution.