The Commonwealth Bank says it is investigating a disruption that has left some customers unable to make payments and view their accounts online.

Key points: CBA investigating problem with NetBank, CommBank app and CommBiz

CBA investigating problem with NetBank, CommBank app and CommBiz Customers report they can't pay with cards or use online banking

Customers report they can't pay with cards or use online banking Bank has not said when the issue will be fixed

In an error message, the bank stated the issue was affecting BPAY, credit cards and loans.

Customers told ABC News they could not view their accounts via the online banking portal NetBank while others were unable make purchases despite having sufficient funds.

People have also reported a number of other issues on social media including being unable to use tap-and-go and the bank's eftpos tablet, Albert.

Technology tracking website Aussieoutages.com reported the Commonwealth Bank (CBA) outages began at 8:00am (AEST) on Wednesday.

In a statement, CBA said it was working on the issue as "a matter of priority".

"We're aware some customers may be experiencing intermittent issues with NetBank, CommBank app and CommBiz," the statement said.

"We know that some merchant terminals are also impacted.

"For our customers impacted by this issue we are sorry, please be assured we are working on this as a matter of priority."

The bank has told users on social media it is unable to say when the problem will be fixed.

Cashless customer stranded

New South Wales resident Bryan (surname withheld) was left stranded on the side of the road after he was unable to use his CBA account to pay a mechanic.

An error message from the Commonwealth Bank. ( ABC News: Rebecca Armitage )

"I had to get a mechanic to come out to fix my flat battery as it had gone flat," Bryan said.

"As I was going to pay him, I was not able to access NetBank in any way, shape or form, which meant I had to make small talk whilst waiting on a response from CBA around what happened."

Bryan said he then went to the mechanic's office to pay but his account was still offline.

"I had to swallow my pride, call my boss and explain and ask her to pay the costs of the replacements," he said.

"Apparently it was going to be sorted by lunch time. It has been four hours since.

"I am still waiting to access my funds to have lunch."

The extended callout caused by the delays meant Bryan was charged an additional $100, which the bank has offered to cover plus compensation for the inconvenience.

Bryan said the experience had not turned him away from CBA.

"Their outages seem to be getting more frequent, so maybe … but I guess all banks have their issues, so probably not bothered enough to leave."

Brisbane resident Jayden Ching was also left unable to pay for a trolley full of groceries after the bank told him he had funds in his account, he just couldn't see them.

"I logged onto my NetBank app to see my weekly wages hadn't gone in yet, however I knew for a fact that I had been paid the day before," Mr Ching said.

"I decided to call them up … [a woman] said the error was simply that clients couldn't view their money but it was in their accounts."

Mr Ching said he tried to pay at the supermarket but his card was declined with a "contact bank" error.

When he checked his card at the ATM outside, it showed his wages were not in the account.

He said he was able to use his card after 2:30pm but could still not access NetBank.