A third severe systems outage for Commonwealth Bank – and the second in a week – will be animating doubts over not just the robustness of core banking systems but the depth in the business case for any return of capital.

At a stretch, it could stir sanctions and shaming by one or more of APRA, ASIC and the Reserve Bank, as payments regulator.

At 1.30pm yesterday CBA confirmed “We are aware of an issue affecting some of our merchant terminals,” – or near enough all of them (with major clients such as Woolworths affected) if the backlash on social media is any guide.

By 2.30pm CBA advised on its Service Page: “We are aware some customers may be experiencing some difficulties logging on to NetBank and the CommBank app right now,” a statement of regret shared periodically on social media over the course of yesterday evening.

“Even the branches had issues” according to social media commentators, with thousands of aggravated personal and business customers of CommBank venting on Twitter and Facebook.

By 11.30pm, the bank seemed more confident that systems were stable, though users were moaning still on Twitter as Banking Day went to press.

Since April, customers have reported problems using the bank’s mobile and internet banking services on 15 days, according to the internet customer monitoring site, Down Detector.

Of the regulators, it is APRA that's allowed CommBank latitude recently.

In November 2020, APRA reduced the operational risk overlay imposed on CBA in 2018 from $1 billion to $500 million, "in response to our significant progress" on the conduct, governance and risk management themes that were the focus of APRA's landmark Prudential Inquiry in the bank.

Surely this perational risk overlay will be reconsidered.