The Bank of Spain (Banco de España), is the national central bank and supervisor of the Spanish banking system. In the case of Spain, the Law of Autonomy of the Banco de España had to be amended to include the authority of the European Central Bank (ECB) to define the monetary policy of the euro area and its powers in respect of exchange rate policy.

Also, it was necessary to adapt the aformentioned Law to the provisions of the Treaty on European Union (TEU), the Statute of the European System of Central Banks (ESCB ) and ECB guidelines and instructions.