On January 1, 2026, Bulgaria will bid farewell to its lev currency and become the 21st European nation to adopt the euro.
The Balkan country of 6.7 million people has been a European Union (EU) member since January 1, 2007, and joined the Schengen Area in March 2024, both of which marked pivotal moments in its integration into Europe.
This leaves only six countries in the 27-member EU still using their own currencies: The Czech Republic, Denmark, Hungary, Poland, Romania and Sweden.
What is the euro?
The euro is the official currency of the EU, serving as the unified currency for its member states and allowing for easier trade and travel among them.
About 350 million people use it, making it the most popular official currency and the second-most traded and held reserve currency in the world after the US dollar.
Managed by the European Central Bank and the Eurosystem, the currency consists of six banknotes, each featuring different European architectural designs, with a seventh note, the 500 euro note, having been discontinued in 2019 but still considered legal tender.
Euro banknotes look the same everywhere, but coins have a national side chosen by each country.
How does a country join the eurozone?
The EU is a political and economic bloc of 27 countries in Europe, formed in 1993 to promote cooperation, free trade and shared policies across the continent.
Most EU nations are legally required to adopt the euro once they meet specific economic criteria. The countries which use the euro are collectively known as the eurozone.
Denmark is the only current member state with a formal opt-out from the eurozone, negotiated in the 1992 Edinburgh Agreement, meaning it has no legal obligation to join the euro.
Before a country can join, it must spend at least two years in ERM II (the Exchange Rate Mechanism). During this time, the national currency is pegged to the euro. If the currency fluctuates too much during this time, the country cannot adopt the euro.
In addition to EU members, four small countries, Andorra, Monaco, San Marino and Vatican City, have formal agreements to use the euro as their official currency, even though they are not in the EU.
When did each country adopt the euro?
The euro was introduced to the financial markets as an accounting currency on January 1, 1999. It replaced the European Currency Unit (ECU) at a 1:1 ratio. Physical coins and banknotes entered circulation on January 1, 2002, fully replacing national currencies by March that year.
The euro was first adopted by 11 countries:
1999: Austria, Belgium, Finland, France, Germany, Ireland, Italy, Luxembourg, the Netherlands, Portugal and Spain.
2001: Greece joined the eurozone on January 1, becoming the first country to adopt the single currency after its initial launch.
2007-2009: Slovenia, Cyprus, Malta, Slovakia.
2011-2015: Estonia, Latvia, Lithuania.
2023: Croatia.
2026: Bulgaria is set to join on January 1, 2026.
