made or allowed to the taxpayer under subsection (e). Any failure to so reduce the credit shall be treated as arising out of a mathematical or clerical error and assessed according to section 6213(b)(1). (e) Advance refunds and credits (1) In general Any person which was a qualifying business for such person’s last taxable year ending before January 1, 2020, shall be treated as having made a payment against the tax imposed by chapter 1 for such taxable year in an amount equal to the advance refund amount for such taxable year, regardless of whether such tax would have been imposed on such person. (2) Advance refund amount For purposes of paragraph (1), the advance refund amount is the amount that would have been allowed as a credit under this section for such taxable year if this section (other than subsection (d) and this subsection) had applied to such taxable year. (3) Timing of payments The Secretary shall, subject to the provisions of this title, refund or credit any overpayment attributable to this section as rapidly as possible. No refund or credit shall be made or allowed under this subsection after December 31, 2020. (4) No interest No interest shall be allowed on any overpayment attributable to this section. . (b) Conforming amendments (1) Definition of deficiency Section 6211(b)(4)(A) of the Internal Revenue Code of 1986 is amended by striking and 36B, 168(k)(4) and inserting 36B, and 6428 . (2) Paragraph (2) of section 1324(b) of title 31, United States Code, is amended by inserting “6428,” after “54B(h),”. (3) The table of sections for subchapter B of chapter 65 of subtitle F of the Internal Revenue Code of 1986 is amended by inserting after the item relating to section 6427 the following: Sec. 6428. Small Business Rebate. . 3. Modification of estimated tax payments for small businesses (a) Timing and amount of required installments (1) In general In the case of any taxable year beginning in 2020, with respect to a qualified individual, notwithstanding section 6654(c) and section 6654(d)(1)(A) of