Australian bank customers are among the world's fastest adopters of mobile banking, a trend that is predicted to make the big four prime targets for technology-based firms eyeing banks' huge profits.

Mobile banking has overtaken online banking through a desktop computer as the main way for customers to interact with their bank, and Australian consumers are leading the charge, consultancy Bain & Company says.

A Bain survey shows 38 per cent of Australian customers' interactions with their bank occurred via a smartphone or tablet in 2014, up from 22 per cent a year earlier. Credit:Getty Images

Survey figures from Bain showed that 38 per cent of Australian customers' interactions with their bank occurred via a smartphone or tablet in 2014, up from 22 per cent a year earlier.

This made mobile banking even more common than online banking, which fell from 42 per cent to 35 per cent of customer interactions.