Commonwealth Bank customers have been left stranded in the midst of the morning rush hour, unable to pay for purchases in the wake of a widespread technology failure affecting credit cards and EFTPOS.
A CBA spokesperson says the cause of the problem, which also affected net banking, mobile banking and BPAY, is being investigated.
Customers trying to log in to the Commonwealth mobile banking app on Friday morning were greeted with a message advising them the bank was "working to restore impacted services as quickly as possible".
Others travelling to work reported being frustrated and embarrassed after not being able to pay for purchases in cafes and shops.
"We are aware some customers are experiencing intermittent issues accessing some of our systems," a spokesperson for the bank said in a statement.
"The cause of the problem is under urgent investigation and we are working to have full services restored as a matter of priority."