United States dollars, accepted all over Indonesia since War World II, are still the most useful foreign currency to carry through these islands. It is very recommended that you always bring US Dollar in Bali. Though the dollar will probably have the most favorable exchange rate, it is possible to cash other well-known currencies like Australian dollars, German marks, Netherlands florins, French and Swiss francs. Canadian and New Zealand dollars are a bit more difficult.
Traveler's checks and cash in U.S. currency can be changed at almost any moneychanger or bank, although changing other currencies can sometimes pose a problem. The smaller towns of Bali may not have banks or, if they do, they may not accept your particular currency. They maybe their noses up at the good old British pound, but they will usually accept crisp US$100 bills. No passport is usually required to change cash.
Change money at the bank in Kuta or Denpasar, which offer the best rates. Large denomination U.S. notes or traveler's checks (100 dollar bills as opposed to twenties) fetch a higher rate of exchange. Obviously, this only really matters if you are going to be changing large amounts.
Indonesian banks, even on Bali, refuse to touch foreign banknotes which are soiled, worn, or physically damaged. If you do a good job taping them with transparent tape, you will probably get away with passing damaged notes off. Banks also will not exchange foreign coins.
Indonesian paper currency tends to stay in circulation longer, so Indonesian banknotes start to take on the appearance of filthy scraps of torn cloth. This worn money will not be accepted, so do not allow it to be passed on to you. If it is, the only place you can change it is at a bank.
Exchange rates depend on the bank and even on the branch of the bank. In some cases, the headquarters bank changes money but their city branches do not. You will need your passport and tourist entry card for each transaction.
In order to encourage tourism and because of he intense competition between moneychangers, the best rates on Bali are in the tourist areas. In the far reaches of the island, such as Amlapura and Gilimanuk, the exchange rates tend not to be as good or there could be no banks at all.
Avoid, if you can, exchanging money at hotel front desks, where you will get at least 10% below the rate offered by state banks. The more expensive the hotel, the worse the rate. The moneychangers at Bali's Ngurah Rai Airport offer very competitive rates. So good in fact that you might as well change several hundred dollars as soon as you land on Bali, to save you time and trouble changing money later.
Moneychangers generally do not charge a fee for their services, so you can change money as often as you want without it costing you. Anyplace tourists congregate will be choked with moneychangers. Though their rates vary, they offer quicker service and usually give a better exchange rate than banks. They also do not open as early but stay open much later than banks. Banks seldom post exchange rates, but moneychangers always do.
Rates fluctuate daily. Check out more than one moneychanger and compare the rates of the currency you have. You could try for a better rate, but you could wear out several cents worth of shoe soles finding it, Pay more attention to finding a place where they do not try to forget the last Rp 300 or give you Rp 500 instead of Rp 5000 and see if you notice.
Count your money to see if it is correct.