Eurozone

The eurozone, officially the euro area and also written "euro zone", is the monetary union of European Union member states that have adopted the euro as their sole legal tender. Its single monetary policy is set by the European Central Bank in Frankfurt, while each country keeps its own government, budget and tax system. With Bulgaria's entry on 1 January 2026, the euro area has 21 members and more than 350 million residents, making the euro the world's second most important reserve currency after the US dollar.

The euro area is a subset of the 27-member EU. It is distinct from the wider European Economic Area and from the Single Euro Payments Area, which covers euro payments in more than 30 countries, including non-members such as the UK and Switzerland.

Imagine a group of neighbouring shops that agree to accept the same tokens and let one shared committee decide how many tokens exist and what it costs to borrow them. Customers no longer have to swap money at each shop's door, and prices are easy to compare along the whole street.

The trade-off is that the committee sets one borrowing cost for everyone. If one shop is struggling while the others are busy, it cannot cut its own rates or make its tokens cheaper. It has to cope in other ways, such as cutting costs, getting help from the others or attracting customers by becoming more efficient.

The euro was launched on 1 January 1999 as an accounting currency in 11 countries: Austria, Belgium, Finland, France, Germany, Ireland, Italy, Luxembourg, the Netherlands, Portugal and Spain. Notes and coins followed on 1 January 2002, replacing national currencies such as the Deutsche Mark, the Italian lira and the Irish pound. Later entrants were:

• Greece in 2001, replacing the drachma.
• Slovenia in 2007, Cyprus and Malta in 2008, and Slovakia in 2009.
• Estonia in 2011, Latvia in 2014 and Lithuania in 2015.
• Croatia in 2023, replacing the kuna.
• Bulgaria in 2026, replacing the lev at the fixed rate of 1.95583 leva per euro.

Denmark has a legal opt-out and pegs the krone to the euro in the ERM II exchange rate mechanism. Other EU members, including Sweden, Poland, Czechia, Hungary and Romania, are committed by treaty to adopt the euro eventually but have not set dates. Outside the EU, Andorra, Monaco, San Marino and Vatican City use the euro under formal agreements, while Montenegro and Kosovo use it unilaterally, a form of euroization.

The Maastricht Treaty of 1992 set convergence criteria that a country must meet before adopting the euro:

• Price stability. Inflation no more than 1.5 percentage points above the average of the three best-performing EU members.
• Sound public finances. A government deficit below 3% of GDP and public debt below 60% of GDP, or falling towards it.
• Exchange rate stability. At least two years in ERM II without severe tensions or devaluation.
• Long-term interest rates. No more than 2 percentage points above those of the three best performers on price stability.

The European Commission and the ECB publish convergence reports, and the final decision is taken by EU finance ministers. National law, especially central bank independence, must also be compatible with the EU treaties.

The ECB and the national central banks of euro countries form the Eurosystem. Its Governing Council sets key rates, conducts asset purchases and their unwinding through quantitative tightening, and runs the T2 payment system. Its primary mandate is price stability, defined since 2021 as 2% inflation over the medium term. Fiscal policy stays national but is coordinated through the Stability and Growth Pact, whose rules were reformed in 2024, and through the Eurogroup of finance ministers.

Since 2014 the largest euro area banks have been supervised directly by the ECB under the Single Supervisory Mechanism, part of banking union, alongside a Single Resolution Mechanism. The ECB has also been preparing a possible digital euro, a central bank digital currency whose launch depends on EU legislation.

The euro area debt crisis from 2010 tested the union. Greece, Ireland, Portugal and Cyprus received rescue programmes, Greece carried out the largest sovereign debt restructuring in history in 2012, and bond spreads in Italy and Spain rose sharply. The turning point came in July 2012, when ECB President Mario Draghi said the bank would do "whatever it takes" to preserve the euro, followed by the Outright Monetary Transactions programme. The European Stability Mechanism, a permanent rescue fund, was set up in 2012. During the pandemic the EU agreed joint borrowing for the NextGenerationEU recovery fund, and in 2022 the ECB created the Transmission Protection Instrument to counter unwarranted spread widening.

Economists still debate whether the euro area is an optimal currency area. Critics argue that members with different economies lost the ability to adjust through the exchange rate without gaining enough fiscal transfers or labour mobility, and that the "doom loop" between banks and their governments raises sovereign risk. Supporters point to lower transaction costs, price stability, deeper markets and the political value of integration, and note that public support for the euro in member states has stayed high. Proposals still under discussion include a common deposit insurance scheme and a permanent central fiscal capacity.

• European Central Bank: the euro
• European Commission: The euro