Exchange Rates

• The credit card company will convert your purchase from euros to dollars at the time that it processes the purchase. The company will use the wholesale rate for currency conversion, which means that you'll get a much better deal than you would get withdrawing cash from a bank or using the currency exchange shop at the airport, according to Bankrate.com. However, currency rates fluctuate on a daily basis, which can mean that a 20-euro purchase one week could be slightly different from a 20-euro purchase another week. You can estimate what the cost will be by looking up current rates online, but the true charge may be slightly more or less.
  
  

Credit Card Fees

• The credit card company will charge a fee to convert money from euros to dollars. This is usually equal to 1 percent to 5 percent of the transaction. Call your bank to learn the exact amount it will charge you. While the fee may not seem like a lot, it can certainly add up, especially if you are making large purchases or several small ones. When traveling, it may cost less to withdraw money from an ATM -- which will also incur a fee -- and use cash when making purchases.
  
  

Your Statement

• The charge on your statement will show up in dollars, rather than euros. Unless you kept your receipts, you will not see the actual exchange rate that the company used. The credit card fees may be wrapped up into the charge shown or it may be listed as a separate fee labeled "foreign transaction fee."
  
  

Potential Credit Freeze

• Most credit card companies actively monitor accounts for activity that may look like fraud. Getting a charge in euros rather than dollars may set off an alarm bell and the company can freeze your account unless you contact the fraud department and verify the charges. This can be especially true when making online purchases, since the credit card company may see a few charges in local American stores and a single European charge. You can alert the company ahead of time to avoid confusion and ensure that your credit card remains available.