Revenue Commissioners have written off more than €1bn in lost taxes from failed businesses over the past decade.
Thousands of firms between 2000 to 2009 did not pass on taxes, which include PAYE, PRSI and VAT collected from employees and customers.
New figures reveal €1.07bn was not collected from 90,100 businesses during the nine-year period.
Businesses hold such taxes in trust and are supposed to pass them on to Revenue at a later date.
Revenue has effectively abandoned any hope of clawing back the money.
According to the Revenue Commissioners, more than €140m was written off in fiduciary taxes between January and September of 2009. Meanwhile, Revenue has recovered €2.6bn from tax cheats since 2001, following special investigations into offshore assets and bogus non-resident accounts.
Almost €1bn has been generated from offshore assets held by Irish residents abroad since investigations started nine years ago, preliminary new figures from the tax authority reveal.
A breakdown of the 2009 figures shows most of money recovered from tax evaders last year came from off-shore assets generating €18.3m. Investigations into bogus non-resident accounts secured €7.7m.
At the end of 2009, there were a total of 114 ongoing investigations into serious tax evasion including 12 before the courts.