To avoid foreign transaction fees (which are typically 3%) in Portugal, the most effective method is to use a travel-focused credit card with no foreign transaction fees, such as the Chase Sapphire Preferred or any Capital One card. In 2026, digital banks like Revolut or Wise are also highly popular; they allow you to hold a balance in Euros (EUR) and pay with a physical or virtual card at the mid-market exchange rate without extra hidden markups. When paying at a restaurant or shop in Portugal, always choose to pay in the local currency (EUR) if the card machine asks you to choose between EUR and your home currency. This avoids "Dynamic Currency Conversion" (DCC), a practice where the local merchant applies a much worse exchange rate than your bank would. Using a no-fee debit card for ATM withdrawals at the official Multibanco machines (rather than the "Euronet" blue and yellow machines) will also save you significant money on withdrawal fees.