On 22 May 2023, the U.S Internal Revenue Service announced that interest rates for overpaid and underpaid tax for the calendar quarter beginning 1 July 2023, which will remain unchanged from the second quarter.

For individuals, the rate for overpayments and underpayments will be 7% per year, compounded daily. Here is a complete list of the new rates:

  • 7% for overpayments (payments made in excess of the amount owed), 6% for corporations.
  • 4.5% for the portion of a corporate overpayment exceeding $10,000.
  • 7% for underpayments (taxes owed but not fully paid).
  • 9% 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 are computed from the federal short-term rate determined during April 2023.