The National Australia Bank (NAB) and the Commonwealth Bank of Australia (CBA) have apologised to customers after both banks experienced outages at the weekend.
NAB confirmed that it suffered a nationwide systems failure as a result of power being cut to its mainframe.
"We had a series of failures today that emanated from a power issue, and it isolated our mainframe. It's an incredibly rare event, but what it did is it took a number of hours for our technicians to be able to bring our systems back up," NAB Business executive general manager Cindy Batchelor told journalists on Saturday.
"When the power goes into the systems, there was a disconnect there that impacted a number of our systems, which provide services to our customers."
The incident resulted in some of NAB's services, including ATMs, Eftpos, internet banking, and mobile banking being out of action on Saturday from approximately 7.50am AEST, with NAB beginning to restore services at around midday.
By 2.30pm, NAB reported all of its systems as back up and running.
"I want to apologise to all of our customers who were impacted by the outage today," Batchelor continued. "We really want to ensure that we provide a reliable service to you, and today we failed to do that. For that, we are sincerely sorry."
At the end of 2016, NAB experienced three system outages in the space of seven days.
The first hit its internet banking, customer call centres, and payments processing as a result of a "number of system outages[1]" experienced the night before.
The bank's customers Australia-wide were then prevented from using their bank cards[2] in ATMs or at Eftpos terminals, with the outage also affecting NAB merchant terminals and