CBP keeps quarterly IRS interest rates for customs duty underpayments and refunds unchanged from October 1, 2026

CBP states in a general notice that the quarterly IRS interest rates used to calculate interest on overdue accounts (underpayments) and refunds (overpayments) of customs duties will remain the same from the previous quarter. For the calendar quarter beginning October 1, 2026, the underpayment rate is 7 percent for both corporations and non-corporations, and the overpayment rate is 7 percent for non-corporations and 6 percent for corporations. The rates are applicable as of October 1, 2026.