They were warning their target about possible fraudulent transactions that urgently needed to be dealt with. Before long, the caller had stolen almost $8000 in an identity theft scam.

"After extensive questioning on my side to ensure the caller would be genuine, I gave in and provided very limited information that he needed to act on my behalf," said the over-55-year-old victim, who wished to remain anonymous.

"Several text messages were sent to my mobile number from the genuine NAB to provide security codes.

"But these had actually been requested by the scammer so he could access my account."

The scammer used his access to change details, including the credit card limit, without the victim being aware. By the time they realised, $7780 had been stolen.

This isn't an isolated incident.

Last year, Australians lost $15.8 million in identity theft scams, though the Australian Competition and Consumer Commission (ACCC) believes this figure is conservative because of under reporting.

Identity theft is the target of this year's Scams Awareness Week from August 17-21.

ACCC deputy chair Delia Rickard said personal information was invaluable.

"Unfortunately, the loss of personal information is a serious consequence of most scams, and often people don't understand how important and valuable their information really is," she said.

"Scammers are no longer just after your money; they want information about you. That's where they can score more financial gain."

Ms Rickard said scammers get personal identifiable information via phishing scams - where the scammers try to gain as much information as they can from you by asking lots of questions.

"If the scammer contacts you by phone they may ask a lot of questions, such as your date of birth, who lives at your house, perhaps even about your superannuation scheme," she said.

"All this information can be used to commit identity crimes.

"The key thing to remember is if someone has contacted you asking for your information, don't give it to them.

"Instead, check whether it's real by contacting the individual or business."

Scams come in lots of different shapes and sizes.

They range from phishing scams designed to steal your information to people impersonating authorities and demanding money they claim is owed.

Here are a few ways you can protect yourself:

Stop and think: Be wary of offers that seem too good to be true.

Scams often try to create a sense of urgency. Don't rush and consider whether it's real.

Don't open or click: Don't open attachments or click on links in unexpected texts, social media messages, pop-up windows or emails, even if it appears to come from a trusted source.

Find and verify: If you're unsure, contact the person, business or agency using contact details you have found independently, for example from a phone book, past bill or online search.

If you think you've been scammed call the police and your bank immediately.