In 1993, the European Council officially specified three conditions to be met for accession to the EU: the "Copenhagen criteria". These prerequisites form the principles and lay down the methods of accession to the EU.
According to the "Copenhagen criteria", a candidate country must have:
- Stable institutions guaranteeing democracy, the rule of law, human rights, respect and protection for minorities
- A viable market economy as well as the capacity to cope with competitive pressure and market forces within the Union
- The capacity to take on responsibilities arising from Member State status, notably respect for policy, economic and monetary targets
In addition, since the European Council of Madrid in 1995, candidate countries must be able to apply Community rules and procedures. They must also prepare for their integration by adapting their administrative structures in order to implement European legislation effectively by means of appropriate administrative and judicial structures. This is an indispensable condition of accession, which is based on mutual trust.
The European Union, for its part, must be capable of integrating new members: it must ensure that its institutions and its decision-making procedures remain effective and reliable. As it expands, it must be in a position to continue preparing and implementing common policies in all fields. Finally, it must be in a position to continue to finance its policies sustainably.
Candidate countries receive pre-accession aid to meet the conditions for accession.