Commonwealth Bank says it is fixing an "issue" that is affecting some of its services, with customers complaining about an outage on social media.

"CommBank banking services, including payments, online access and ATMs are being restored," the bank said in an update on its website at 12.45 pm AEST.

"We apologise for any inconvenience and thank you for your patience."

Commonwealth Bank didn't say what caused the problems, referring to it only as an "issue" in its statement.

"Some of our services were unavailable for approximately an hour before they started being restored," a spokesperson told the ABC.

Commonwealth Bank has yet to post about the issue on social media, however customers have been commenting on previous posts to air their grievances.

"App down again can't pay for petrol,

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