Auckland Savings Bank (ASB), part owned by the Commonwealth Bank of Australia, has launched its Facebook customer service application, Virtual Branch.
The bank will offer real time customer service assistance over the social network site.
ASB will also break with Facebook culture, assuring customers that "live chats will not be posted on your wall".
The service hooks up customers with the bank's specialists, ASB claims on its Facebook launch page, and promises service levels equivalent to its branches.
The Virtual Branch is available seven days a week between 8 am and 9pm, with ASB's FastNet Classic service the fall back option after hours.
ASB said it used 128 bit SSL encryption to secure conversations on Virtual Branch.
The service has pipped National Australia Bank's UBank, which has limited its Facebook presence to publishing, for example, an outage which occurred last Saturday.
Australian banks were reported to be testing Telstra's T-Hub device to extend mobile phone applications to the home sphere back in March.
Westpac-owned St George Bank and National Australia Bank have also said they would develop applications for Apple's iPad, while the Commonwealth Bank and ANZ Bank were optimising existing websites for tablet screens.