Landlords and holiday home owners who do not pay charges and fees owed on properties that are not their main residences could face penalties of over €7,000 from next month.
The fees apply per property with owners of multiple units paying multiple fees.
The Non Principal Private Residences (NPPR) charge came in in 2009 and has since been abolished.
However, late fees apply to unpaid amounts.
The NPPR was a charge on any private residence that was not someone's main home such as a holiday home, someone who owned more than one home, or owned a property but rented elsewhere.
The total cost for the five years up to 2013 was €1,000.
Those who have not paid now incur late fees and penalties.
Those liable for all five years owe a total of €4,220 by 31 August.
After that they will incur additional penalties of up to some €3,000 - a total of €7,230 when all penalties are applied, in some cases.
More than €425-500m has been processed by the agency which administers the NPPR so far.
Dublin City Council has issued 6,000 letters to people who may now be liable for charges.
The Irish Property Owners Association has called for an amnesty on the penalties associated with the charge.
They have described the fees as 'unfair'.
The Department of Environment has said there is no intention to change the arrangements at the moment.
Owners are warned that any charges or late payment fees due will have to be discharged, in full, before the sale of a property can be completed.