The U.S. IRS has announced the interest rates for overpaid and underpaid tax for the calendar quarter beginning 1 April 2018, which are increased from the previous quarter due to an increase in the federal short-term rate. The rates are 5% for both overpayments and underpayments by individuals, and 4% and 5% for corporate overpayments and underpayments, respectively. The rate for corporate over…