Bulgaria and the euro a stable ERM-II member for a minimum of two years. While Bulgaria has not formally joined the exchange rate mechanism, the ±15% floating band permitted within ERM II is less restrictive than Bulgaria's current strict peg of 1.95583 BGN to 1 EUR. The lev has been pegged to the euro since its launch, and prior to that was pegged on par to the German Mark. While the currency board which pegs Bulgaria to the euro has been seen as beneficial to the country fulfilling criteria so quickly, the ECB has pressured Bulgaria to drop it as it did not know
Currency board to other domestic considerations, and that the fixed exchange rate will, to a large extent, also fix a country's terms of trade, irrespective of economic differences between it and its trading partners. Typically, currency boards have advantages for small, open economies which would find independent monetary policy difficult to sustain. They can also form a credible commitment to low inflation. More than 70 countries have had currency boards. Currency boards were most widespread in the early and mid 20th century. Hong Kong operates a currency board (Hong Kong Monetary Authority), as does Bulgaria. Estonia had a currency board fixed to