IR-2023-154, Aug. 25, 2023 WASHINGTON — The Internal Revenue Service today announced that interest rates will increase for the calendar quarter beginning Oct.1, 2023. For individuals, the rate for overpayments and underpayments will be 8% per year, compounded daily. Here is a complete list of the new rates: 8% for overpayments (payments made in excess of the amount owed), 7% for corporations. 5.5% for the portion of a corporate overpayment exceeding $10,000. 8% for underpayments (taxes owed but not fully paid). 10% 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. Generally, in the case of a corporation, the underpayment rate is the federal short-term rate plus 3 percentage points and the overpayment rate is the federal short-term rate plus 2 percentage points. The rate for large corporate underpayments is the federal short-term rate plus 5 percentage points. The rate on the portion of a corporate overpayment of tax exceeding $10,000 for a taxable period is the federal short-term rate plus one-half (0.5) of a percentage point. The interest rates announced today are computed from the federal short-term rate determined during July 2023. See the revenue ruling for details. Revenue Ruling 2023-17PDF announcing the rates of interest,will appear in Internal Revenue Bulletin 2023-37, dated Sep. 11, 2023.