On my way to Vientiane for a SETV and due to the holiday on Friday, I will be there till Monday/Tuesday. Best to use Dollars or Baht, get dollars here or there? Thanks :-)
TLDR : Answer Summary
In Vientiane, both Thai Baht and US Dollars are accepted, but it's advisable to convert money into Lao Kip for better rates. Using Baht is convenient, but some vendors may charge a higher conversion fee. It's recommended to use local banks for currency exchange to get a good rate. If you need to show a sum of K20,000 (approximately $800) when returning to Thailand, it's feasible to withdraw Kip and exchange it into Baht, although getting dollars directly from ATMs may not be possible.