The IRS has announced that interest rates for both overpayments and underpayments of individual taxpayers will remain at 7% for the calendar quarter beginning Jan. 1, 2026. For corporations, the rate for payments exceeding the amount owed will be 6% (4.5% for corporate overpayments of more than $10,000). For large corporations, the underpayment rate will be 9%. For other corporations, the rate will be 7%. In general, overpayment and underpayment rates are determined by adding a certain percentage to the federal short-term rate, as dictated by the Internal Revenue Code. Interest is compounded daily.
