On April 23, 2021, US Customs and Border Protection (CBP) published in the Federal Register a general notice that advises the public that the quarterly Internal Revenue Service 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 April 1, 2021, the interest rates for overpayments will be 2 percent for corporations and 3 percent for non-corporations, and the interest rate for underpayments will be 3 percent for both corporations and non-corporations. This notice is published for the convenience of the importing public and U.S. Customs and Border Protection personnel.