The checks were worth 353 trillion rials ($1.07 billion), down 10.6% on a monthly basis, the Central Bank of Iran reported.
Bad checks accounted for 8.2% of total drawn checks, and 10.5% of the volume of all checks issued in the month.
In the corresponding period last year 9.7% and 12.6% of the volume and value of all drawn checks were rejected.
Bad checks accounted for 9.1% and 11.4% of the total drawn checks in the fifth month of the Iranian year.