The Euro currency was introduced and adopted by 11 Member States.
The Euro was introduced as an accounting currency in 11 member states on 1 January 1999. The Euro banknotes and coins started to circulate on 1 January 2002. The Euro coins have a common side and a national side, which indicates the issuing country.
After February 28, 2002, the Euro became the sole currency of 12 EU member states, and their national currencies ceased to be legal tender.