Commonwealth Bank of Australia has apologised for a data centre failure which locked customers out of internet and mobile banking and hit card payments for most of Monday.

In a statement, Pete Steel, executive general manager in charge of digital retail banking services at the Australian, confirmed the data centre downtime, which afflicted customers for the best part of Monday.

"We have two data centres that support the app and NetBank and unfortunately one of them has had an issue and so there is a lot of demand on one data centre," he says. "If customers are struggling to log on, I’d encourage them to wait five or 10 minutes and try again. My sincere apologies, and we are working as hard as we can to get the issues fixed."

Despite priding itself on its credentials as a market leader for digital banking, this glitch is the second in a four-month period to hit customers. In April, customer complaints flooded in after a series of major outages left them unable to access their bank accounts over a full 24-hour period.