ANZ Bank has confirmed it has fixed an outage to its online banking services that has caused disruption for thousands of customers for four hours, a day out from Christmas Day.

An ANZ spokesperson said a system outage between 10.30am and 2.30pm on Tuesday caused "intermittent issues" for people logging into its goMoney app and internet banking services.

"All other services, including debit and credit cards, PayWave, EFTPOS, ATMs and payment processing continued to work normally and were not impacted.

"The outage has now been resolved, however some customers may have still experienced slight issues as the backlog was cleared.

"We apologise to our customers for the inconvenience caused."

According to Downdetector, a site which monitors internet outages, nearly 5500 customers had reported an outage between 10am and 2.30pm.

An error message shows for ANZ customers trying to access their accounts online.