Tax revenues last month came in slightly under target, according to the latest exchequer returns, published this afternoon.
In total, the state took in €21.71 billion in May, down 1.1% or €253 million on what was expected.
However, compared to the first five months of last year, the tax take is up 5.7% or €1.166 billion.
Income tax receipts were 7.8% ahead of where they were in May 2018, while corporation tax revenue was €233 million or 11.4% behind where it had been expected to be.
According to the Department of Finance, next month will provide a clearer picture of the corporation tax performance this year, as May is the last month of collection for 2018, a year where income from companies was higher than had been anticipated.
Excise duties were in line with expectations during the month, but were 6.2% higher than target compared to the first five months of 2018.
Stamp duty, however, was almost half of what had been forecast for the month, although for the year to the end of May receipts stand at 2.9% behind where they were last year.
The picture around non-tax revenue and capital receipts was stronger than that surrounding tax intake, with the total income rising 18% or €597 million year on year to €3.92 billion.
When tax and non-tax revenues are combined, the exchequer earned 7.4% more in the year to the end of May than it did in the same period last year.
Overall though, the exchequer had recorded a deficit of €62 million by the end of May, almost three times more than the shortfall recorded during the first five months of 2018.
Net voted spending came in broadly in line with expectations, down just 1% below what had been anticipated in last year's budget.
But compared to the same period last year, it was up significantly by 8% or €1.55 billion.
Non-voted spending was also considerably above where it was a year ago, driven mostly by a higher contribution to the EU.
In total non-voted expenditure to the end of May came in at €4.8 billion or 5.4% higher than it was 12 months ago.
Peter Vale, Tax Partner at Grant Thornton said the corporation tax figures could be of some concern to the Minister.
"The Department of Finance had previously cautioned that 2019 would see a dip in corporate tax receipts due to one off factors in 2018," he said.
"However the deficit against target is of concern."
"That said, June is an even more significant month for corporate tax receipts and will provide an even better indication of where the figures for the year will land."
Davy Chief Economist, Conall MacCoille, also pointed to the corporation tax issue.
"Thankfully, Central Bank surplus income and spending inside generous government targets have made up for the shortfall, with the items that feed into Ireland’s balance actually €178m ahead of expectations," he said.