The disadvantage of using currency abroad is that carrying too much cash can dramatically increases your risk of becoming a victim of crime.
Hence, the advantages to using other financial instruments are considerable.
In most countries, credit cards, ATM cards, and check and debit cards are accepted although with varying levels of compatibility. The downside is the risk of fraud.
Be aware of the following:
Foreign Exchange transaction. Before arriving at your destination, print a copy of the currencies used, and learn what they look like by denomination.
Not knowing the currency and exchange rates can result in both legitimate and black market money-changers intentionally or accidentally cheating you;
Credit Card Switch. The credit card returned to you after you make a purchase is not yours. Instead, it is an expired or stolen card.
Always examine your card when merchants return your card to you and verify that it is yours;
Credit Card Fraud. If possible, observe that merchants process only one transaction.
Dishonest merchants, assuming you will never check your statement, can process two or more transactions.
I returned home from a trip to Colombia to find more than $3,000 in charges on my card for tires and auto parts.
Always check your statement. Before you sign for a transaction, ensure that your name of the merchant is printed on the transaction slip; and
Police Impersonating Money-Changers. In many countries where currency is tightly controlled, dishonest police will often impersonate a money-changer.
When a foreigner uses a black-market and unauthorized money-changer, the police officer identifies himself and demands several hundred dollars in exchange for not arresting him/her.
Convert currency at authorized vendors only.