Revenue Ruling 2013-25 provides the rates for interest on tax overpayments and underpayments for the calendar quarter beginning January 1, 2014.  The interest rates will be 3 percent for overpayments (2 percent in the case of a corporation), 3 percent for underpayments, 0 and one-half percent for the portion of a corporate overpayment exceeding 10,000, and 5 percent for large corporate underpayments.  This quarterly determination is required by section 6621 of the Internal Revenue Code.