THE CBA says "routine maintenance" triggered a major glitch affecting its online, electronic and phone banking.
The computer malfunction has prevented online money transfers and BPAY, and is also affecting EFTPOS, ATM and phone banking.
While the problem was first reported this morning, the issue continued to frustrate customers as the day neared close of business.
Banking customers today were unable to transfer money from their accounts or pay bills as the bank suggested people with urgent transactions should visit a local bank branch.
CBA spokesman Steve Batten said it was investigating the problem which had occurred last night during “routine database maintenance”.
Mr Batten said full banking services were expected to resume this afternoon.
In the meantime, affected services included funds transfer through NetBank, CommSee Bpay and phone banking channels.
Some EFTPOS and ATMs were also affected, he said.
“The CBA understands the potential impact these matters can have on our customers and apologises for the inconvenience,” Mr Batten said.
The bank said its NetBank system was still online, but also reported that scheduled payments due today would be delayed until “later today”.
In a statement the bank urged customers to “bear with us while we investigate and resolve this issue”.
Many users reported frustration at the problems, with some concerned they would be charged for overdrawing their accounts, or failing to meet payment deadlines.
Others tweeted that they were unable to get through to the Netbank hotline.
In December, the bank was hit by a separate computer problem that left about 5 per cent of its customers without access to their money.
The problem was tracked down to a lagging computer file.
A corrupt file triggered late payments for thousands of NAB customers in November, while its online banking system went offline for about eight hours in late January.
The malfunction comes a day after the bank launched an app for Android-enabled phones, with the bank estimating 20 per cent of log-ons were now done over mobile devices.
The CBA said its mobile banking platform had been “been modified for Android to enhance the mobile banking experience with customised screen sizes and resolution, along with faster processing time”.
Mr Batten said the latest banking issue was unrelated.
