The Revenue Commissioners are cracking down on the number of homes that were "significantly undervalued" in property tax returns.
According to The Irish Times, officials are targetting those that were estimated to be worth "far lower" than guide values from May 2013.
Nearly a quarter of a million people estimated that their property value was more than €100,000 below the guideline amounts issued by the Revenue Commissioners in May 2013.
Homeowners could have to pay back tax if officials believe the amount declared does not reflect the market value.
To date, some 7,800 property owners have voluntarily revised their property valuations upwards. In many cases, this was done before putting a home on the market.
In Dublin, homes selling for more than 25 per cent of their declared values are required to provide evidence to substantiate their original valuation; the level is set at 15 per cent in the rest of the country.
