IR-2007-154, Sept. 4, 2007 WASHINGTON — The Internal Revenue Service today announced there will be no change in the interest rates for the calendar quarter beginning Oct. 1, 2007. The interest rates are as follows: 8 percent for overpayments (7 percent in the case of a corporation); 8 percent for underpayments; 10 percent for large corporate underpayments; and 5.5 percent for the portion of a corporate overpayment exceeding $10,000. 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 0.5 of a percentage points. The interest rates announced today are computed from the federal short-term rate based on daily compounding determined during July 2007. Revenue Ruling 2007-56 PDF will appear in Internal Revenue Bulletin No. 2007-39, dated Sept. 24, 2007. Subscribe to IRS Newswire