Figures released by the Department of Finance show that the Exchequer surplus for the first seven months of this year was £2,992m, compared with £3,589m at the same stage last year.
Total tax receipts were up 5.6% to £13.3bn, a growth rate of less than half of what was predicted at Budget time.
Income tax receipts were up from £3,910m to £4,193m, while VAT and Corporation Tax receipts were also ahead, but excise duties dropped from £1,885m to £1,754m.
Expenditure was up by over 20% to £10.1bn.
Last month, the Department said it expected the surplus for the year as a whole to be £500m lower than predicted at Budget time.
