Revenue has said it expects waiting times on its Local Property Tax helpline to be longer over the next few days ahead of the deadline for online returns.
Property owners have until Wednesday 27 November to file online returns.
Revenue's Vivienne Dempsey told RTÉ's Today with Sean O'Rourke programme that it expects an increase in calls between now and the deadline.
She said: "As of this morning, I think the waiting time around eight o’clock was only a couple of seconds, but we expect as the day goes on that that will increase.
"I would say bear with us. This is the reason we've extended the lines from eight in the morning until eight at night to allow time for people to call. But do call and if you need assistance we're there to help you."
Anyone who qualified for a deferral or exemption, chose to pay at source (through pay or pension) or by direct debit last year was not contacted by Revenue because that method of payment will continue throughout 2014.
Ms Dempsey said there should be no confusion between those currently buying and selling homes as to who is liable for the property tax next year.
"The liability date, the first of November, was in the legislation from day one and that legislation was published in December 2012," she said.
"If you owned the property on the first of November any year from now on you are going to be liable for the tax. So you just factor that in to the buying and selling price that you'll agree for the house."
Local Property Tax helpline: 1890-200-255.