On August 19, 2010, the IRS announced that interest rates for the calendar quarter beginning October 1, 2010, will remain the same as follows:
1. Individual underpayment and overpayment: 4%;
2. Corporate overpayment: 3%
3. Large corporate underpayment: 6%
4. Portion of corporate overpayment exceeding $10,000: 1.5%
The interest rate is determined on a quarterly basis and compounds daily. 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 of a percentage point.
Interest factors for daily compound interest for annual rates of 1.5 percent, 3 percent, 4 percent, and 6 percent are published in Tables 8, 11, 13, and 17 of Rev. Proc. 95-17, 1995-1 C.B. 556, 562, 565, 567, and 571.