WASHINGTON — The Internal Revenue Service today announced that interest rates will decrease for the calendar quarter beginning July 1, 2020. The rates will be: three (3) percent for overpayments [two (2) percent in the case of a corporation]; one-half (0.5) percent for the portion of a corporate overpayment exceeding $10,000; three (3) percent for underpayments; and five (5) percent for large corporate underpayments. Under the Internal Revenue Code, the rate of interest is determined on a quarterly basis. For taxpayers other than corporations, the overpayment and underpayment rate is the federal short-term rate plus 3 percentage points.