NAB's latest IT glitch locks customer accounts

National Australia Bank is experiencing an online banking outage that has blocked some customers from accessing their accounts.

The bank confirmed the glitch at 10:20 AEST on Monday morning, however customer reports appear to indicate the problems started around 9:00 am.

“We’re aware of a tech issued where some customers have had their internet banking accounts incorrectly blocked and received a text advising them to call NAB,” the bank said via Twitter.

“We’re investigating a fix for this.”

While the bank is not saying how many people are affected, it said the cause of the glitch was the accidental imposition of a block to stop fraudulent transaction. 

"We apologise to some customers who have this morning been impacted by an error which incorrectly placed a fraud block on some accounts, restricting access to internet banking," a NAB spokesman said.

"We can assure customers that this is an error and their account is secure. Our teams are working to resolve this issue as soon as possible. We thank customers for their patience and understanding."  

Then latest incident comes just days after it was revealed the number of high severity customer facing IT incidents have again started to climb at the transforming institution.

Rivals are dining out on the NAB's bad reliability run, with Westpac CEO Brianb Hartzer showboating its zero 'Severity 1' record for the past two financial halves at that bank's interim results on Monday.

NAB's customers have reported receiving texts alerting them to their blocked account and asking them to call the bank.

@NAB received this text and its already an hour that am trying to contact. pic.twitter.com/NoGAYn00Nj

— Rabi Ghimire (@rabishghimire) May 5, 2019

Thanks For Wasting My Time @NAB! Sending Out Incorrect Warnings & Locking People’s Internet Banking. Still No Access! #NAB #NABFail 2.0!

Sort It Out!!! pic.twitter.com/z5WHmOOnze

— Michael Bassett (@AndNowItsTime) May 5, 2019

The bank has advised customers to visit a branch or call to have their accounts unlocked, though has acknowledged that “wait times are quite high due to this issue”.

NAB has experienced seven “critical incidents” in the last six months to March – its highest number of outages over the last three years.

The bank defines critical incidents as “significant impact or outages to customer facing service or payment channels”.

NAB has suffered glitches to online banking and apps each month this year so far. The worst of these was in January, when the bank experienced an outage that it later put down to problems with its data centre.