The local currency is the Cambodian Riel. However, US Dollar is widely accepted and easily exchanged across the country. In larger city and town, most goods and services are priced in US dollar and it is necessary to buy some riels as it's used for change below 1 dollar. In more remote areas, prices are quoted in riel (except for accommodation).
In some districts, particularly Poipet, Pailin and Koh Kong, Thai Baht is widely used. Traveler's cheque in US Dollar can be changed at most banks in the capital Phnom Penh and Siem Reap as well as in all major tourist destinations. Credit cards are well accepted in all major tourist Regions. Although, it is advisable to carry some US Dollar in cash. ATMs can now be found and available in many major tourist capitals in the Kingdom. Almost all of them dispense in US dollar.