It's best to take Indonesian Rupiah to Bali. If you can't buy some before your trip, the next best options are Australian Dollars (AUD), US Dollars (USD) or Euros (EUR). You can easily change these 3 currencies almost anywhere on the island.
Do they accept USD in Bali?
Bali is the largest of 17,508 islands that make up Indonesia and the Indonesian Rupiah is the only currency accepted in all of them. However, as Bali receives a lot of tourists on vacation Australian Dollars (AUD), American Dollars (USD) and Euros (EUR) are sometimes accepted and can be exchanged for IDR on the island.