Westpac said crews are investigating the issue, but did not confirm what the problem is.
“We’re aware some customers are experiencing issues accessing banking services,” a spokesperson said.
“We’re working to restore services as quickly as possible and apologise to customers for the inconvenience.”
According to DownDetector, customers began experiencing issues just before 1pm.
At the peak, more than 1000 people reported an issue with their services.
