The Bank of Spain is the Spanish member of the Eurosystem and has been the monetary authority for Spain from 1874 to 1998, issuing the Spanish peseta. Since 2014, it has also been Spain's national competent authority within European Banking Supervision. It was originally established by Charles III in Madrid in 1782, as the Banco Nacional de San Carlos, and took its current name in 1856. Its activity is regulated by the Bank of Spain Autonomy Act. The bank doesn't translate its name to English but uses its Spanish name in all English communications.

The Eurosystem is the monetary authority of the eurozone, the collective of European Union member states that have adopted the euro as their sole official currency. The European Central Bank (ECB) has, under Article 16 of its Statute, the exclusive right to authorise the issuance of euro banknotes. Member states can issue euro coins, but the amount must be authorised by the ECB beforehand.