EU membership also includes the obligation to treat exchange rate policy as a matter of common interest. Among other things, this means that the newly acceding countries are expected to join the Exchange Rate Mechanism of the EU.
They need not necessarily participate in this exchange rate system immediately upon joining the European Union, but, depending on the specific circumstances in the individual candidate countries, this step may also be taken later. The prerequisite for the last step 3  BIS Review 30/2000  adopting the euro and thus participating fully in EMU - requires sustainable fulfillment of the Maastricht convergence criteria.