"Aggressive" scammers masquerading as the taxman have ripped more than $1 million from innocent Australians so far this year, prompting a fresh round of public warnings.

Scammers are increasingly employing iTunes gift cards as a payment method, with one victim losing $60,000.

The Australian Competition and Consumer Commission says more than 300 people have reported losing more than $1 million in total to tax scams in the first half of this year.

To compare, 400 people reported losing $1.6 million last year.

The watchdog is urging the public to hang up on phone calls or delete emails from suspected scammers, who are ramping up their activities during the tax return period.

Tax scams come in many guises, but generally fraudsters claim you have underpaid your taxes and are required to immediately repay the debt, otherwise you could be arrested.

"Tax scammers are particularly aggressive so many people feel pressured to pay quickly without questioning them," said ACCC's deputy chair Delia Rickard.

"The most threatening scammers even say that police are on their way to arrest you but can be stopped if you pay immediately."

Earlier this year, Fairfax Media shared the story of North Shore resident Sue Bull who was sent into "panic mode" when two "forceful and quite intimidating" voice messages said the Australian Tax Office had taken out a writ against her for tax fraud.

She followed the directions and spoke to a man purporting to be an ATO employee.

"He gave me an identification number for the tax office and a case file number and he knew my personal details. It's a degree of sophistication that is mind-boggling."

She said if her husband had not stepped in and encouraged her to hang up the call, she likely would have given her banking details.

The ACCC says scammers harvest personal information from the internet to convince you they're legitimate.

They usually demand for immediate payment via wire money transfer, credit card, direct debit and even iTunes cards.

In May, Victorian grandmother Glenice Harrison lost $5000 after fraudsters instructed her to clear her alleged tax debt by buying iTunes gift vouchers at two Woolworths stores.

There have been reports of one person purchasing $60,000 worth of iTunes gift cards to settle a fake debt, while an elderly couple bought $18,000 worth.

"In April 2016, of the 8692 phone scam reports we received were in relation to the fake ATO tax debt scam; 58 reports mentioned the scammer demanding payment by iTunes and 26 people unfortunately paid $174,830 to fraudsters," said ATO's assistant commissioner Janine Clark.

"By the time these scams are reported to us, the cards have already been on-sold or redeemed by the scammers," she said.

"The scammers don't need the actual physical card. They just need the gift card number, which they get victims to read over the phone."

The ATO also reminded the public that while it makes thousands of calls to taxpayers, it would never cold call someone about a debt or threaten arrest. It would also never request personal information via email.

"If you receive a call or email out of the blue from someone claiming to represent the ATO and that you are entitled to, or owe money – just hang up or press delete," said Ms Rickard.

Protect yourself

• If you receive an email or phone call out of the blue from 'the ATO' claiming that you are entitled to a refund, that you owe money or asking you to confirm, update or disclose confidential details like your tax file number, press 'delete' or just hang up.
• The ATO advises that you should be very careful with whom you share your tax file number. Never put your tax file number (TFN) on your resume or share it on social media.
• You should change your passwords if you have shared them with anyone, including family and friends.
• Don't reply to suspicious emails, open any attachments or click on any links – they may take you to a bogus website or contain a malicious virus.
• Always keep your computer security up to date with anti-virus and anti‑spyware software and a good firewall.
• If you think you have provided your account details to a scammer, contact your bank or financial institution immediately.

(credit: Australian Competition and Consumer Commission)

Do you know more: ehan@fairfaxmedia.com.au