For hotels, there is no issues when you book online. So make sure you choose the right card to avoid currency conversion fees and get the best points multiplier! Many restaurants and some businesses accept credit cards, but there is sometimes a 2-3% fee for its use. Bali is still a place where cash is king. So, I suggest you always have some cash on hand in case you want a spontaneous $8 massage or a $1 coconut while walking on the beach!