BANKING / CURRENCY
Exchanging dollars is relatively easy in Costa Rica and dollars are widely accepted. Costa Rica's national currency, the colon fluctuates in value to the U.S. dollar and has drifted downward against the U.S. currency in recent years, with the banks paying about 563 colones for $1 in January, 2010.
You can get local money when you arrive at San Jose's Juan Santamaria international airport or the international airport in Liberia. However, if you aren't able to do this when you land, there are state and private institutions that offer both local and international banking services and can exchange foreign currencies, provide cash advances on credit cards (though not all banks take American Express) and cash travelers checks. Use the ATM’s that have been introduced in San Jose and many of Costa Rica's smaller cities to withdraw colones against your credit or debit cards.
Banks are generally open from 9 AM to 3 PM; a few have extended hours. You may need to be prepared for a wait, though; lines and bureaucracy can make getting money at banks an endeavor that requires a bit of time and patience. Most hotels can exchange money or cash your traveler’s checks, but you may take a hit on the exchange rate. As is standard for all travelers, changing money on the streets is a ‘buyer beware’ scenario. If you prefer not to carry a lot of colones, most international credit cards are widely accepted in Costa Rica, as are U.S. dollars.
Remember to keep your dollar denominations small as bills such as hundreds or even fifties may not be accepted. U.S. dollars are best for travelers checks as well, since those denominated in other currencies are not commonly accepted. Make certain to countersign travelers checks EXACTLY as you did when you purchased them. Banks will not accept travelers checks with variations in signatures from vendors, consequently vendors will not accept them from you. In the same manner, vendors and banks are similarly wary of signature variations on credit card transactions. To avoid potential problems it is best to sign credit card receipts in the exact way you signed your card.
Ideally you will want to carry some colones while in Costa Rica, especially if you plan on traveling to out of the way places. Small hotels, restaurants and shops may not accept anything but colones.