“But what we see, especially in situations of domestic violence, are examples of abusive partners making payments such as child support payments, but instead of a large payment, they may make some 50 smaller ones, leaving a separate abusive or threatening message for their ex-partner on each.”

The NAB system instantly recognizes 1,300 words and phrases – as well as special characters replaced with forbidden words and phrases – and blocks the transaction.

Australia’s Electronic Security Commissioner, Julie Inman Grant, said she was pleased to see banks building ‘security by design’ into systems.Credit:Louie Douvis

Customers receive real-time messages advising them to change the wording if they want the transaction to continue.

Blocked transactions are reviewed and warnings are issued in some cases.

Some messages are so threatening that NAB employees reading them have been referred for help.

“With people I know, as well as my own experience, it’s a bit like when you get nasty text messages – you feel sick and you feel deeply unsafe in your own home,” Ms Katerinskaja said.

“Transaction messages are the last place you would expect it.”

NAB personal banking group director Rachel Slade said transactions intended to convey abuse were often for amounts as small as 1¢ or 5¢.

“It’s not even about the money,” she said.

Other banks have similar programs. Appearing before a parliamentary hearing in September 2021, Westpac chief Peter King said his bank had blocked 21,000 such messages that year.

The bank had issued 767 warning letters and reported 54 customers to the police and the regulator, AUSTRAC.

In November, AUSTRAC chief executive Nicole Rose said the agency was concerned about the increased use of financial transaction fields for domestic family violence and criminal activity.

Ms Slade said NAB customers had been referred for help, but the bank had yet to involve the police.

“Comments from victim-survivors indicate that the behavior may have very serious consequences for them…Our job is to protect clients without giving them advice on what to do,” she said.

If you or someone you know needs help, you can contact the National Sexual Assault, Domestic and Family Violence Advice Service on 1800RESPECT (1800 737 732), Lifeline 131 114 or Beyond Blue 1300 224,636.

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