The currency shared by the 19 countries that formed the euro area in 2015 was the euro.
Lithuania became the nineteenth euro-area member on 1 January 2015. It adopted the euro at the fixed conversion rate of €1 for 3.45280 Lithuanian litas. This enlargement followed Estonia’s adoption in 2011 and Latvia’s adoption in 2014, completing the Baltic states’ transition to the euro.
The euro area has expanded and changed since 2015, so the figure of 19 describes its membership at that specific time rather than its current total. The European Central Bank and the national central banks of participating countries form the Eurosystem, which is responsible for the common monetary policy.
The euro’s ISO code is EUR, and euro notes are identical across participating countries apart from their serial and printing details. Coins have a common European side and a national side, allowing each country to show local symbols within the shared currency system.