The Taoiseach says the Revenue Commissioners have made it clear that their property valuations are merely an indication.
Letters will be sent to 1.8 million homes around the country over the coming weeks, detailing how the new property tax should be paid.
They contain a valuation of the property - which was criticised yesterday by industry experts for failing to take into account the number of rooms or square meterage.
Speaking on his way into Government Buildings this morning, Enda Kenny said it is up to homeowners to challenge that valuation, if they feel it's incorrect.
"I think the Revenue Commissioners, in setting out their letters, did clearly say these are indications only and it is a matter for each individual house owner to determine the valuation of their property."