The bank says usage of smart phones on the group's mobile banking channels has grown by 90% in the last 12 months, with mobile activity now accounting for 30% of all online sessions, growing 150% over the past year.

Jason Yetton, group executive, Westpac retail & business banking, says: "Banking is being transformed by the use of technology such as smart phones and these figures prove that this trend is only going to accelerate."

The primary users of Westpac's mobile banking app are small to medium-sized enterprises, who conducted 3.5 billion transactions on their handsets over the past six months. SMEs make up 15% of the current active Westpac mobile banking user base.

In total, the bank is currently processing two million mobile banking sessions a week and says that 10% of mobile customers now only use this channel to move their money around and no longer sign on via a PC.