ACC is not expecting the $100 million it's refunding to have much of an impact on its operations.
The Accident Compensation Corporation has discovered two historical overpayment issues with its levy system, dating back 16 years.
Spokesman Phil Riley told Larry Williams just over 100,000 self-employed people will get refunds of about $340 - and another 200,000 businesses will get back about $400.
"Whilst the amount is significant and we accept that, in context of what we earn in a given year from earners and work account, it is really negligible. It is .37 cents of the income we received over that period."
LISTEN TO PHIL RILEY TALK WITH LARRY WILLIAMS ABOVE