The currency is the Lao kip (LAK), which comes in relatively small notes (the largest denomination equals about $12). Though the kip has stabilized in recent years, and most prices are now listed in kip, we've chosen to list all hotel rates in U.S. dollars. The Thai baht is accepted in Vientiane, Luang Prabang, and border towns. It's best to carry most of your cash in dollars or baht and exchange relatively small amounts of kip as you travel. At this writing, the official exchange rate is approximately 260 kip to the Thai baht and 8,000 kip to one U.S. dollar.
There are now ATM machines throughout the country so changing money isn't a big issue anymore.
Credit cards are accepted in most hotels and some restaurants, but few shops. Banks in major tourist destinations will provide a cash advance on a MasterCard or Visa, typically for a 5% service charge. Western Union has branches in Vientiane and other major towns.