All EU Member States, except Denmark, are required to adopt the euro and join the euro area. To do this they must meet certain conditions known as 'convergence criteria'.
In order to adopt the euro, EU countries have to bring their national legislation in line with relevant EU law and meet specific conditions designed to ensure economic convergence. These requirements, agreed by the EU Member States in Maastricht in 1991, are known as the convergence criteria.
The Convergence Reports examine whether the Member States satisfy the necessary conditions to adopt the single currency.
Changing a whole economy from one currency to another is a complex process that requires careful preparations at many levels of society. One decision to be made is how the euro will be introduced: each EU country must choose among three possible scenarios the one which best meets its needs.
Changing over to another currency is a major operation which requires massive preparations in order to ensure a smooth transition.