Revenue has admitted it made a blunder on payment demands for the property tax - but insisted it was only trying to deliver the best service possible.
Tax boss Josephine Feehily faced down challenges from politicians about controversial letters sent to homeowners asking for credit card payments for next year's bills this month.
The letters neglected to say there were other ways of paying the tax next year.
Attempting to explain the ill-judged communication, Ms Feehily said she thought people would be fully aware of all the other payments options and that offering seven different options was a good thing.
"It's almost as if the extra piece of service has caused more problems," Ms Feehily said.
Revenue sent letters to almost a million homeowners telling those planning on using a debit, credit card or cheque they would have to pay this month.
It explained this was due to a data protection matter - that Revenue could not retain card details.
Ms Feehily defended the fact Revenue does not retain credit card details, insisting homeowners would not want it to be able to "dip in" and take money whenever it wants.
"We do not retain credit card details. It's unsafe, there are privacy issues, there are risk issues," she said.
Ms Feehily said she was "intrigued" by the fact there was "virtually no complaints" earlier this year when homeowners were asked to pay their first property tax bill more than a month in advance of the deadline.
She said had this been a problem at the time, Revenue may have communicated the payment methods differently this time round.
"I think we assumed that people might still have their local property tax (LPT) booklet and that there had been so much printed and said about this tax only five or six months ago, that people would be somewhat familiar with the concept and the language and so on," Ms Feehily added.
"So we pared the letter back to its absolute basics. Clearly this was a mistaken assumption on our part."
The commission chairwoman said there was clearly "some anxiety" surrounding the payment method for the tax, but she insisted there are people who actually want to pay the bill "to get it out of the way before Christmas".
She added that the online payment system flagged to people making a debit or credit card payment that their payment would be taken there and then.
However, she admitted this system should have included a notification to customers that there are alternative payment methods.
Ms Feehily also confirmed that post-dated cheques sent in advance of January 1 would be cashed immediately.
Apart from a single payment, other payment options include phased payments and setting up a direct debit to pay the tax in 12 monthly instalments.
"As a service we are offering seven different payment options for LPT which allow property owners to decide whether to pay now, next year or in phased payments," Ms Feehily said.
"No one has to pay the LPT before January 1 unless they choose to do so. Many taxpayers are telling is that they want this option and the figures support that. We have, for those who don't want that option, five other ways to pay in 2014 providing both phased payment and single payment options. Again, the choice is with the taxpayer but they have to tell us now."
As of this morning, tax returns had been filed for 205,000 properties.
Ms Feehily said this, combined with payment options that were rolled over from 2013, gives a compliance rate of 35%.