The only catch was they required the local man to pay $499 up front to "avoid paying ongoing tax".

Athol Briden of Cooranbong wasn't born yesterday.

But he admits that the scammers were convincing ... at least to begin with.

"The caller introduced himself as Tom Wilson from the Ministry of Justice, and said that he was representing customers from all banks who had been overcharged," Mr Briden said.

Being aware of legitimate class actions taken against banks, Mr Briden at first thought the caller was fair dinkum.

The caller provided the contact details for his "supervisor", if Mr Briden had any doubts.

He explained that Mr Briden would be taxed year after year on the $9640, and to avoid it could make the one-off payment of $499 "before 5pm tonight".

When the caller became insistent on an immediate credit card payment, Mr Briden became suspicious.

"I offered to write him a cheque and asked who I should make the cheque out to. But he became agitated and evasive," Mr Briden said.

"He nearly persuaded me until he started insisting that I pay by 5pm. What's wrong with paying tomorrow?"

Mr Briden took notes during the call.

After hanging up, he visited his local bank branch with the details and was advised not to take any notice of the call because it was a scam.

Mr Briden estimates that he was on the phone for half an hour, and that the man had an Asian accent.

His advice to locals is simple.

"If you are in any doubt, check with your bank. I did."