A good tip is to carry multiple credit cards and a little cash. Merchants may impose credit card surcharges in some places.
Credit cards such as American Express, Bankcard, Diners Club, MasterCard, Visa, UnionPay and JCB are accepted in Australia. VISA or MasterCard can be used everywhere credit cards are accepted. American Express and Diners Club are accepted at major supermarkets, department store chains and tourist destinations.
Traveller's cheques are not widely accepted in Australia. If you do purchase traveller’s cheques, it is best to buy them in Australian dollars as smaller shops, restaurants and other businesses are unlikely to know what the exchange rate is if you present a cheque in a different currency such as US dollars or British pounds.