In total, 64,294 calls have been received by the Revenue services overseeing the imposition of the controversial new charge, which kicks in on July 1.
As of last Friday, Revenue had sent out 1,193,154 letters containing estimated tax bands for 1,351,289 properties covered by the levy.
Owners have until May 7 to return the forms by post, and May 28, online, and if they do not estimate their own valuation for the property, the Revenue one will stand.
Some 59,956 forms have now been returned, but considerable confusion remains regarding the estimations, with calls to the helpline hitting a one-day record of 9,612 last Thursday.
A spokesperson for the Revenue urged householders to be honest when they estimate values.
"This is a self-assessed tax, which means that you assess the value of your property having regard to the guidance available, your knowledge of the property and the local area.
"Revenue is asking property owners to engage reasonably and honestly with the process, and their self assessment will be accepted.
"The band system means you don't have to be precise and Revenue does not expect people to pay for a professional valuation.
"Revenue has engaged extensively with local authorities in order to obtain lists of their properties that can be matched to Revenue's database. Because there was no existing complete register, and because there will be difficulties in matching the addresses, letters will issue to tenants in a minority of cases.
"It is most important that you don't ignore the letter because, in the absence of any correction, Revenue will proceed on the basis that you are liable to pay property tax in respect of the property," the spokesperson said.
