On 15 August 2022, the Internal Revenue Service announced that interest rates will increase for the calendar quarter beginning October 1, 2022.

For individuals, the rate for overpayments and underpayments will be 6% per year, compounded daily, up from 5% for the quarter that began on July 1. Here is a complete list of the new rates:

  • 6% for overpayments (5% for corporations). (payments made in excess of the amount owed)
  • 3.5% for the portion of a corporate overpayment exceeding $10,000.
  • 6% for underpayments. (taxes owed but not fully paid)
  • 8% 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, for 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 are computed from the federal short-term rate determined during July 2022.