A mistake in the laws around the property tax has cost the State €3 million.

Finance Minister Michael Noonan has confirmed that the Revenue Commissioners are refunding the €3 million this year to people who were actually exempt from the tax.

The law was intended to exempt first-time buyers who were purchasing a second-hand home.

However a mistake means the credit applies to all people who bought a second-hand house.

500,000 people have already sent returns for the tax next year, which has raised €215 million so far this year.

Householders have another eight days to file their returns online. However the figures do not say how many people have already paid the 2014 tax.