The sale of more than a quarter of the State's shares in AIB is the primary reason behind a recent boost in Exchequer funds, the Department of Finance has said.
Latest figures show the Exchequer with a surplus of almost €3.37bn at the end of July.
€1.1bn more in tax revenue has been collected during 2017 to date compared to the same period last year.
Tax revenue for July was €119m (or 2.6%) below target, while the 2017 figures in total are 0.8% below target.
Expenditure for the year to date, meanwhile, totalled €31bn.
In this month's Fiscal Monitor, the Department of Finance says: "An Exchequer surplus of €3,366 million was recorded to end-July 2017. This compares to a surplus of €862 million in the same period last year.
"This year-on-year improvement of €2,505 million is primarily due to the recent sale of over 28% of the State’s shareholding in AIB."
The statement adds: "As highlighted previously, there were a number of large one-off income tax payments in April 2016, amounting to c. €100 million. Excluding these, the underlying tax position is showing a year-on-year increase of 4.9% or €1,301 million."
