The Revenue Commissioners have received more than 637,400 local property tax returns to date, less than three weeks ahead of the filing deadline.
More than 441,500 of the returns have been made electronically, according to Revenue figures, while almost 195,900 have been paper-based.
Tuesday was the deadline for paper-based returns, with 28 May set as the deadline for electronic filings.
There were close to 2 million dwellings registered by the Central Statistics Office during Census 2011, although not all of these would be liable to pay the property tax.
Revenue said its Local Property Tax Helpline had received more than 294,000 calls to date.