This will depend on the duration of your stay and the money you spend on local handicrafts. Some visitors like to carry hefty sums because they want to buy souvenirs and gifts for their family and friends back home. Some bring very little cash because food, accommodation, vehicle, guide etc… is covered in the tour price and they don’t want to do shopping. We highly recommend you to bring USD dollars for shopping in Bhutan because it’s widely accepted in handicraft stores and other stores. There are few ATMs in Thimphu where you can withdraw money with your credit card but we would advise to you carry cash in USD for convenience.