Almost one in five people selling their homes say they cannot afford the mortgage on it, according to a recent survey.
The study by MyHome.ie also found that one in four say they set a lower value for their house when calculating Property Tax than the estimate suggested by Revenue.
The website's managing director Angela Keenan says there is a lot of concern among homeowners about the tax.
"Under two-thirds went with the Revenue figure an in fact 11% went with a higher figure," she said.
"But also what was interesting was a couple of issues that buyers are facing - a number of prospective buyers are absolutely worried about the prospect of paying property tax for a full year."