More than half of those who underpaid their taxes continued to be non-complaint four years later, while one fifth had actually got worse, the Comptroller and Auditor General John Buckley has found.
The figures relate to the years before 2002 as Mr Buckley also found that the Revenue Commissioners have not carried out a programme of re-audits on non-complaint tax payers since 2002.
Presenting the results of his audit of the Revenue accounts for 2007 today, Mr Buckley told the Dáil Public Accounts Committee €47 billion in taxes had been collected in 2007.
The figure compares with an estimated €37 billion this year.
Mr Buckley said there was a risk that up to 30 per cent of tax payers underdeclare the amounts of tax they owe.
Given the figures for "recidivism", he said the audit processes should be the "cornerstone" of revenue collection.
But Mr Buckley concluded it would be difficult to ascertain the effectiveness of audits or to calculate the rate of recidivism in the absence of follow up audits in subsequent years.
Mr Buckley also found that "automatic write-offs" of less than €1,000 per case amounted to €2.5 million in 2007 - up from less than €1 million in 2006.
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