Financial Tips

Prior to departing the United States, several steps may be taken to prevent financial difficulties abroad.

Contact your credit card agencies and banks to inform them of your intent to travel abroad and the planned location and duration of your travels. Fraud departments at these companies actively monitor credit card activity for unusual actions including purchases abroad; even with this notification they may still freeze your card until you communicate directly to state that you are travelling abroad.
Ensure that any ATM cards are accessible on the international networks and are not limited to the United States. In many cases this will not be an issue. If you have a very long PIN, verify that the ATM's abroad will be able to accept it.
Prepare for arrival in your destination country by exchanging an initial amount of currency prior to departure. This will negate the need to delay activity upon arrival and may help with any transportation or other fees at the destination.
Investigate the opportunity to have online banking made available for your accounts to manage funds while abroad. If you access your funds from abroad, take care to access sensitive financial material only from computers that you trust.
Do not rely on the ability to open a bank account in foreign countries; this may be extremely difficult or in some cases impossible.
ATM availability may vary widely even from town to town; prepare for this prior to travel.
Banks vary widely in the fees charged for transactions made in foreign currencies. See Don't Get Fleeced by Fees on Vacation from the Motley Fool(29 May 2007). If you plan to make credit purchases abroad, consider finding a bank or credit union that offers low fees.
Credit cards offer more protection for both lost/stolen cards and for disputed transactions than debit cards do. See The Best Travel Credit Cards (March 15, 2017) from Time's Money.com for some cards with added travel perks.
Cash Cards are also an option - these are prepaid cards that can act as debit, credit, and ATM cards (details vary).
Investigate value-added taxes (VAT) and goods and services taxes (GST) information - you may be able to recuperate the tax upon departure if you follow procedures at purchase time. See Value-Added Tax Refunds fromRickSteves.com for an introduction to the process.
Using credit cards abroad: Advice on Using Credit Cards While Traveling Abroad (New York Times)