Two separate network issues have left Commonwealth Bank customers unable to access their own money or process other people's payments.
The problems Commonwealth Bank's online banking system ran into early on Monday dragged throughout the day as thousands of people made countless attempts to pay for groceries, bills and fuel.
Brisbane man Bobby Skidmore said he had to head into a branch and login using the bank's own computers in order to ensure he had enough money to fill up his car's fuel tank.
He'd tried more than 20 times to access the system from 4am.
"If I hadn't checked first then I would have been stuck with a fuel bill I couldn't pay," he told AAP.
"I needed to visit a chemist for medications for my ear and had no way to transfer funds to pay."
Concurrently, those using Visa cards issued by other banks were unable on Monday to make payments at businesses using CBA EFTPOS terminals.
As the bank sought to fix the payment issue, it asked businesses to switch to manual procedures including credit card imprinter plates.
CBA business customers went to the length of recommending other payment services on the bank's own Facebook page.
Canberra cafe owner Dan Rayner lambasted the bank as he was unable to process any transactions on his CBA-issued Albert tablet terminal.
"You guys have created an environment heavily dependent on electronic transfers and you have no back up when things go wrong?" he posted online.
"Our customers now no longer carry cash - we are losing business."
The bank at 4.30pm said some customers were still having issues logging into NetBank and the CommBank app.
"We understand this is very frustrating and we apologise - we're working to restore services as soon as we can," the bank posted online.
The bank has also told customers payments using the PayID system were taking 48 hours.
They are normally processed in minutes.
