As misunderstandings go, it's a whopper.

National Australia Bank has admitted they got it wrong when they called the cops and told them father-of-two Adrian Everett was threatening to shoot his 18-month-old baby.

Mr Everett had done nothing of the sort - he had just been a bit snarky when NAB's collection agents rang on Tuesday night.

But he had done nothing that required three armed police to come to his house on Tuesday night, waking up his two young boys and scaring them "s***less".

A NAB operator had just misheard something he said, thought a child was in danger, and called in the cops.

NAB spokesman George Svigos said the bank apologised to Mr Everett after reviewing audio of the phone conversation and determining "that at no time did the customer make a threat against the safety of his children".

"NAB apologises to Mr Everett over this incident," he said.

"We have reviewed this specific matter and have determined that our operator misinterpreted a comment made by the customer to be a threat to the safety of one of his children.

"We are sorry for what has occurred and have attempted to discuss our review of this matter with Mr Everett on a few occasions over the past 24 hours."

Mr Everett yesterday told news.com.au that the police turned up on his doorstop, told him there'd been a report, and demanded to check on his children.

"I am really concerned that the image of police coming into my young children's room may stick with them for a long time and could have lasting effects on them," Mr Everett said.

Mr Svigos said they had given a copy of the audio recording to police, and would do the same for Mr Everett; he added that they would review their processes, and emphasised that NAB take the safety of children seriously.

"These are often highly complex judgements," he said.

News.com.au has contacted Mr Everett to ask whether he is satisfied with the apology.