The interest rate for overpayments and underpayments for the third quarter of 2026 are one percentage point higher than in the previous quarter. For July 1, 2026, and through September 30, 2026, the IRS interest rate charged on underpayments for individuals increases to 7%, while large corporate underpayments are charged 9% interest. The interest rate that the IRS pays to individuals on overpayments (generally this means refunds not issued within 45 days) is also 7%, while the rate for large corporate overpayments exceeding $10,000 is 4.5%. #IdeaoftheDay
