Dublin City Council is to try to recoup over €1m worth of bin charges dating back at least five years.
The council's legal department has decided that of the total outstanding debt of €6.9m over 80% is uncollectable, but efforts will begin to trace debtors who owe the rest, a total of €1.2m.
A report to councillors on the Finance Committee said the debt remains on the records of the council's waste management system.
It states that most are uncollectable either because of their age, bills being issued to "The Occupier" or amounts being too small to be economically viable.
The debts date back to 2011 before the city council transferred waste collection to Greyhound Recycling.
At one stage the debts amounted to €13.8m, with most of the 140,000 customers owing at least bills for the last quarter of 2011.
When Greyhound took over at the start of 2012 it was to collect the debts as part of its agreement with the council but outstanding bills were later handed over to a Cork-based debt collection company.
The council says it will now re-engage with Greyhound to see how to proceed with the outstanding debt.
Chairman of the Finance Committee Cllr Ruairí McGinley (Ind) said a significant amount of money is involved.
"It is disappointing this was not pursued more aggressively at the handover. At the time you have some chance of collecting the money, four years later you have no chance."
The report to councillors states that while the debts have officially been written off and do not appear in the annual accounts that does not mean they are not collectable.
