As customers contended with yet another NAB system outage – its third in a week and second in as many days – the bank is still refusing to reveal the source of the issue.

And banking experts say we may never know the real reason for the IT failures.

A National Australia Bank spokesperson confirmed customers had been left without access to online banking on Tuesday, while payments to customers had also been impacted.

“Our teams are working hard to monitor our services and ensure the stability of systems for our customers,” the spokesperson said in a statement.

And despite continued reassurances that the technical issues have been fixed, NAB has again failed to provide customers details as to what is going on.

“A thorough review of the issues that have arisen in the past week is underway,” the spokesperson said.

NAB declined to comment despite repeated requests from The New Daily to elaborate further on the outages.

Experts say we may never know what caused the issue if the system’s security was to blame.

“It’s not transparent, we will never know the security or the safety of their information technology so that just adds to the uncertainty,” University of Wollongong banking and finance expert Paul Mazzola told The New Daily.

“Banks have historically spent a lot of money on information technology so is money the answer? Is throwing more money at these systems the answer? Or are these systems flawed? It just raises way too many questions as to what is going on.

“I think we are all waiting with bated breath to know in specific detail what’s been going on,” he added. “When there is this much uncertainty [customer] confidence suffers.”

‘The bank is doing self–harm’

Customers aren’t the only ones left inconvenienced by NAB’s electronic banking service outages. The bank itself is also paying a price.

“The bank would definitely not like it because it would be costing them money,” Unhappy Banking advocate Geoff Shannon told The New Daily.

“This would certainly be hurting them because all banks are now focussing their revenue on transaction fees, on fees being generated by ATMs and over the counter sales rather than lending, so it would certainly be hurting the bank.”

NAB chief customer officer Andrew Hagger’s statement below:

A message to our customers pic.twitter.com/YTFhDGiAoH

— NAB (@NAB) October 11, 2016

Mr Shannon predicted there would be “panic to the consumers” if NAB disclosed the system outage was a result of a security issue.

“The reason why they are not going to say anything is if someone was hacking into their system, they would definitely not want to mention that because it could create a bit of an issue with their clients.

“They would all be concerned if their money was safe.”

Mr Shannon added that even if it was just a system malfunction, NAB wouldn’t disclose the problem.

He said they have a responsibility to their shareholders and a potential run-on could create hysteria.

Furious NAB customers

For the second time in 48 hours, NAB customers took to social media to vent their anger over the embarrassment and outrage the system outage caused.

what about the people with other banks who are waiting for wages to be transferred through your bank.we can't access any money grrrr

— Sharon ann davey (@Sharonanndavey1) October 11, 2016

Mr Shannon said he was also inconvenienced as a result of NAB’s episode.

“I’m an asthmatic and I went to the chemist yesterday, and luckily I had $9 in my pocket because the terminals weren’t working,” he said.

“Certainly if I didn’t have that $9 I would have been seriously inconvenienced. I probably would have had to have made a trip to the hospital.”