Hundreds of thousands of Robodebt victims could miss out on thousands in compensation if they fail to register for a fresh class action settlement before a looming deadline.

The federal government agreed to pay $475 million in compensation to victims of the Coalition's "illegal and immoral" Robodebt scandal – the largest class action settlement in Australian history.

Gordon Legal – which launched the class action lawsuit – said that while 100,000 impacted Australians have signed up for the compensation, hundreds of thousands more could miss out.

NSW man Justin is among the 443,000 Australians who were delivered a crushing Robodebt notice.

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