Which European country adopted the euro on January 1, 2026, becoming the 21st member of the eurozone?

Bulgaria recently took a significant step in its European integration by adopting the euro on January 1, 2026, officially becoming the 21st member of the eurozone. This move marks a culmination of a long process that began when Bulgaria joined the European Union in 2007 and committed to eventually replacing its national currency, the lev, with the euro.

The transition to the euro involved Bulgaria meeting stringent economic convergence criteria, often referred to as the Maastricht criteria. These benchmarks cover areas such as price stability, sound public finances, exchange rate stability, and long-term interest rates. The Bulgarian lev had already been pegged to the euro at a fixed exchange rate since 1999, which helped stabilize the currency and minimize economic disruption during the changeover.

Leading up to the adoption, the European Commission and the European Central Bank conducted assessments to confirm Bulgaria's readiness. Following positive reports, the European Parliament and the Council of the European Union provided their final approvals in July 2025. For a month after January 1, 2026, both the lev and the euro circulated in parallel for cash payments, with the euro becoming the sole legal tender as of February 1, 2026. This historic transition is expected to bring benefits such as greater economic stability, smoother cross-border transactions, and increased integration within the European single market.