The currency on Bali is Indonesian Rupiah – IDR.
1 AUD = approximately 10,500.00 IDR
1 Euro = approximately 16,260.00 IDR
Some of the shops in the main tourist areas accept credit cards and there are also lots of ATMs and currency exchange offices available, but if you want to explore “off the beaten path”, have cash ready. Taxis, local shops, fresh produce… none of them would have credit card terminal.
It is better if you exchange cash at home before traveling rather than rely on ATMs. This is the mistake we’ve made. In Seminiyak we found a Commonwealth ATM, but yet we still had to pay withdrawal fee (even though we have Commonwealth Bank in Australia) and the ATM would not let us to withdraw more than 1,000,000.00 IDR at once, which is less than 100 AUD. Indonesian biggest note is 100,000.00 IDR (less than 10 AUD).