The official currency of Greece is the Euro (EUR). You can exchange foreign currency into Euros at banks, exchange offices, and ATMs, which are widely available throughout the country. Credit cards are widely accepted in Greece, especially in larger cities and tourist areas. Visa and Mastercard are the most commonly accepted credit cards, while American Express may not be accepted at smaller establishments. It's always a good idea to carry some cash with you, especially if you plan to visit more remote areas or smaller villages where credit card acceptance may be limited. It's also important to notify your bank and credit card company before your trip to Greece to avoid any issues with card usage. Some banks and credit card companies may charge fees for international transactions, so it's important to check with them beforehand to avoid any surprises.