INCREASE IN RATE OF INTEREST PAYABLE ON LARGE CORPORATE UNDERPAYMENTS.

SEC. 11341. INCREASE IN RATE OF INTEREST PAYABLE ON LARGE CORPORATE UNDERPAYMENTS. (a) General Rule.— Section 6621 (relating to determination of rate of interest) is amended by adding at the end thereof the following new subsection: “(c) Increase in Underpayment Rate for Large Corporate Underpayments.— 104 STAT. 1388–471 “(1) In general.— For purposes of determining the amount of interest payable under section 6601 on any large corporate underpayment for periods after the applicable date, paragraph (2) of subsection (a) shall be applied by substituting ‘5 percent-age points’ for ‘3 percentage points’. “(2) Applicable date.— For purposes of this subsection— “(A) In general.— The applicable date is the 30th day after the earlier of— “(i) the date on which the 1st letter of proposed deficiency which allows the taxpayer an opportunity for administrative review in the Internal Revenue Service Office of Appeals is sent, or “(ii) the date on which the deficiency notice under section 6212 is sent. “(B) Special rules.— “(i) Nondeficiency procedures.— In the case of any underpayment of any tax imposed by this subtitle to which the deficiency procedures do not apply, subparagraph (A) shall be applied by taking into account any letter or notice provided by the Secretary which notifies the taxpayer of the assessment or proposed assessment of the tax. “(ii) Exception where amounts paid in full.— For purposes of subparagraph (A), a letter or notice shall be disregarded if, during the 30-day period beginning on the day on which it was sent, the taxpayer makes a payment equal to the amount shown as due in such letter or notice, as the case may be. “(3) Large corporate underpayment.— For purposes of this subsection— “(A) In general.— The term ‘large corporate underpayment’ means any underpayment of a tax by a C corporation for any taxable period if the amount of such underpayment for such period exceeds $100,000. “(B) Taxable period.— For purposes of subparagraph (A), the term ‘taxable period’ means— “(i) in the case of any tax imposed by subtitle A, the taxable year, or “(ii) in the case of any other tax, the period to which the underpayment relates.” (b) Effective Date.— The amendment made by subsection (a) shall apply for purposes of determining interest for periods after December 31, 1990.