Over 380 thousand households have failed to file a property tax return, despite a high profile campaign by Revenue last year.
The failure to report means those households are now likely underpaying their property tax.
November 10th last was when every household in the country was supposed to submit the latest valuation for their property, so they could pay new rates of L.P.T.
According to this mornings Irish Independent 19% of homeowners have so far failed to submit their property's value, meaning they're still paying at 2013 rates.
Revenue also says that of those who have registered - 54% have valued their property at less than € 262,000, despite property prices increasing in value by 13.5% in the year to October.
People who choose to pay the tax for a full year by cash or cheque will be due to pay by this Wednesday, while those paying by Direct Debit can expect the money to be taken on the 15th of January - and every month after that on the 15th.