Bono and Ryanair boss Michael O’Leary could save thousands in a controversial tax based on how their homes have been valued on the Revenue Commissioners’ new website.

Eyebrows have been raised by the new property tax, with homeowners expected to accurately assess what to pay the government based on the value of their houses.

The tax is assessed based on the value of a home. It is 90 if the property is worth under 100,000. The amount payable increases with every extra 50,000 the home is valued at. If it is worth more than 1 million the tax is 1,800 and for every extra 1 million the tax goes up another 2,500.

The tax will be introduced in July, but this week the Revenue Commissioners have issued an online website to assist householders when making personal assessments of the tax due.  That’s why eyebrows have been raised.

U2 singer Bono’s home at Vico Road, south Dublin, a detached house built before the year 2000, is among a group of homes priced on the site at between 550,000 and 600,000. That would mean Bono paying just 1,034 a year in the new tax.

But his mansion is estimated to be worth several million euro. It is estimated that the real value of Bono’s house is about 2.5 million, putting the tax due at a minimum of 2,775 a year – two and a half times more than is assessed on the website.

O’Leary’s country pile in Gigginstown, Co. Westmeath, is also reckoned to be grossly undervalued and would leave him liable to tax of only 157 for a full year.

Terraced homes in Howth, Co. Dublin, once a major attraction during the property boom, are still valued at between 300,001 and 350,000. But real estate agents maintain their true value is much less with one home in the area going for 130,000 earlier this year.,

Ronan Lyons, economist with, Ireland’s number one property website, said the system is vague because it doesn’t allow for the different sizes of homes.   

He said the Revenue Commissioners didn’t have all the key information for the assessment website like the numbers of rooms and the square meterage of a house. That meant a “relatively vague” value of the property appeared on the site.

He said, “That presents issues in Dublin and the rest of the country, where values are vastly different. In the case of a large, new detached property that is beside another and appears on paper to be the same, may be a much smaller property.”

Revenue Commissioners have begun distributing tax forms to 1.8 million householders nationwide this week. Property owners who believe the revenue estimate is wrong will be able to appeal.