At present, the euro area comprises 19 Member States:
On 1 January 1999, as stage III of economic and monetary union began, the euro was introduced in the 11 founding euro-area Member States: Austria, Belgium, Finland, France, Germany, Ireland, Italy, Luxembourg, the Netherlands, Portugal and Spain. On 1 January 2001, Greece joined the euro area.
Until the end of 2001 the euro existed as book money only (cheque, transfer, payment by card) and its use was voluntary (no compulsion – no prohibition). Euro coins and notes were introduced on 1 January 2002, when use of the euro became compulsory and national currencies were progressively withdrawn.
From 2007 on, the euro area gradually expanded as more Member States joined: Slovenia (1 January 2007), Cyprus and Malta (1 January 2008), Slovakia (1 January 2009), Estonia (1 January 2011) and Latvia (1 January 2014). On 1 January 2015, Lithuania became the 19th euro area Member State.