Dynamic Currency Conversion
It gets even worse if you are using a non US$ card. DCC insists on doing the transaction in US$. That means first you’ll lose on the exchange to US$ to €. Then you’ll get hit again when your bank converts to your own local currency. Pennies following pennies out the door. Finally don’t feel not using an ATM will keep you safe. Some merchants also provide DCC. Always for their benefit. How to protect yourself? Make sure any transaction is done in the local currency. If you’re in an Euro area country pick Euros. Never blindly accept a transaction in US$. Unless of course you’re in the US.
No matter if you are standing at the ATM or in shop or with a waiter hovering next to you DON’T rush. Take the seconds to read the screen and know what you’re accepting. Look if the transaction is in the local currency. Check for any added fees. In some countries only non bank ATMs add fees. Or potentially only some bank ATMs. If anything seems strange just cancel the transaction and take your card to a different machine.