ING Direct is tapping start-up Bump Technologies for the feature on its updated iPhone app for Electric Orange current account customers.

Users send money to each other by entering a dollar amount into ING Direct's mobile Person2Person Payment feature and "bumping" their iPhones to initiate an instant payment between accounts.

ING says it is the first US bank to use the bump technology. When PayPal added the feature to its iPhone app last year, it was downloaded over a million times in its first three weeks.

Arkadi Kuhlmann, CEO, ING Direct, says: "Today, cash is no longer king. Only seven per cent of ING Direct Electric Orange Checking Customers say they pay primarily with cash. With Bump technology, ING Direct customers can leave the cash at home knowing they have a smartphone in their pocket."