The potential windfall, expected to cost the Govt $300million, is the result of reforms to compulsory third-party insurance.
The most a private car owner can receive is $125 and the minimum is $10, with the amount dependent on when you renewed your green slip, your vehicle type, and where you are located.
To find out if you qualify for a refund and how much you are due, you can go to Service NSW online between 7pm and 7am Monday to Saturday, and all day Sunday.
The unusual timing is to spread the extra load the refund process has put on their system.
You will require a MyServiceNSW account and your bank details to apply for the refund. For those who don’t yet have an account, it can be set up within minutes.
Motorists have until September 30 to claim their refund.