Revenue has apologised after confirming thousands of pensioners were taxed incorrectly this month.
The error meant over 5,000 pensioners paid too much tax after Revenue applied the wrong tax credits and rate bands to some pensions.
The mistake affected people with an occupational pension along with the State PRSI weekly pension.
It occurred following the upload of Department of Social Protection pension information to Revenue's records.
In a statement, Revenue said the errors meant "some taxpayers have had more tax deducted from their occupational pension or salary in February than should have been the case".
"We regret any inconvenience or upset caused to individual taxpayers as a result of this error."
The story was first reported in today's Irish Independent.
Revenue added that the problem will be resolved in the next pension or salary payment made by the pension provider or employer.