Online banking services have been restored for National Australia Bank customers, after the third system outage in a week left them unable to access their money online for more than three hours.

The processing of some customer payments was also affected, and the bank said it was still working to restore those services.

“NAB services are back online following an outage earlier today,” the bank said in a statement.

“There may be a delay in the receiving of some payments and we’re working to process these as soon as possible.

“Thank you to our customers for your patience, we understand that this has been inconvenient.”

While the bank had said ATMs and in-store card facilities had not been affected, complaints on the company’s Facebook page suggested otherwise, with some customers saying they had been unable to pay for fuel and groceries.

Tuesday’s outage comes after a system failure on Wednesday last week that prevented customers from being able to log on to their internet and mobile banking, delayed a number of transactions and impacted call centres.

There was another outage on Monday morning but it was resolved within a couple of hours.

The bank said it was monitoring the situation.

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

“We are committed to improving the performance of our technology and investing in our systems.”

NAB’s first Facebook post about 11am Tuesday

 The second post about 11.15am Tuesday