It is not necessary to bring riel with you; the primary currency is dollars and if you need riel this can be changed easily in the country. Travellers cheques and credit cards can be cashed in Phnom Penh, and most currencies can also be easily exchanged.
Money changers in Phnom Penh usually offer much better rates, without commission, than exchange bureaus overseas so if you are arriving during working hours you may wish to wait and change money when you get here. We can take you to change money the day before your trip if you’d like some help with this. Some larger provincial capitals can also take travellers cheques and credit cards. There are also ATMs in Phnom Penh, Sihanoukville, Battambang and Siem Reap, among others, which accept Cirrus, Maestro and Visa.
When heading into the countryside, it’s best to carry low/medium denomination dollar bills. $50’s and $100’s are easy to change in cities and large towns but less useful in more rural areas. Also be aware that faded or torn large denomination bills may often be refused.