The Chief Executive of the Local Government Management Agency has said that the figure for the exact number of households liable to pay the Household Charge is not clear.
Paul McSweeney said there were a number of households throughout the country that will never appear on the Household Charge register, due to exemptions, including for property held in trust and charity, Health Service Executive, Government and local authority housing.
He said nobody knows the exact figure for the number of liable households.
Socialist Party TD Joe Higgins has claimed the figure is 1.8 million. The Environment Department maintains the figure is about 1.6m.
Mr McSweeney said households entitled to a waiver, for example a household in an unfinished housing estate or in receipt of mortgage interest supplement, should have registered for that waiver.
He said waivers would become part of the register, and were included in the estimate of 805,000 properties registered by last night's deadline. He said this estimate was conservative and was expected to rise.
Mr McSweeney said the agency expected to have a reasonable indication of how many people had registered for the charge before the deadline by Wednesday lunchtime.
However, he said it would take a number of weeks to get a final definitive figure.
Minister for the Environment Phil Hogan this afternoon said that in excess of 800,000 households had registered and paid the charge by the close of business yesterday.
He said that the LGMA was also expecting what he termed "a massive influx" of postal applications to arrive next week.
The minister said that he was examining the principle of rewarding any local authorities that “pull out all the stops” to collect the charge.
A spokesperson for Mr Hogan confirmed that each local authority will receive a county-by-county breakdown of what they collected shortly.
The spokesperson reiterated the statement made by Minister Hogan on a number of occasions recently that local services will face cuts if all the money is not collected.
She also reiterated that the department is sticking by its estimate that 1.6 million households were liable for the Household Charge, despite claims by others the actual figure is much higher.
In addition, the minister's spokesperson confirmed Mr Hogan is contesting a bill for private management fees that relate to an apartment he owns in Portugal.