Banks, telcos and Internet companies like Google are among those who will fight the war to have the default app for mobile payments, they said.

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The goal of the digital wallet is to mirror a real wallet, said Visa country manager Vipin Kalra. It can hold credit, debit and store loyalty cards and any other payment methods, he said. Digital wallets are "live in the US today [and] coming to Australia soon".

A digital wallet leader may emerge later, but "in the short term, there will be a whole bunch of apps," said PayPal Australia head of mobile business Paul Buchanan. "There isn't one right now that does it all." Buchanan said he does not view requiring users to flick between multiple digital wallets as an inconvenience.

Kalra disagreed: "At the end of the day, consumers won't want to carry too many wallets." The winner will be the wallet that is "accepted by all major merchants," he said. "Open and ubiquitous acceptance are the two key words that will eventually win the battle."