allowed to the taxpayer under subsection (g). 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). Taxpayers would be held harmless. (2) Joint returns In the case of a refund or credit made or allowed under subsection (g) with respect to a joint return, half of such refund or credit shall be treated as having been made or allowed to each individual filing such return. (e) Advance refunds and credits (1) In general Each individual who was an eligible individual for such individual’s first taxable year beginning in 2019 shall be treated as having made a payment against the tax imposed by chapter 1 for such first taxable year in an amount equal to the advance refund amount for such taxable year. (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 first taxable year if this section (other than subsection (f) 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 on a monthly basis and a pro rata amount for partial universal emergency rebate period in the first month of the implementation of this Act. No refund or credit shall be made or allowed under this subsection after the COVID–19 outbreak is over, as declared by the Secretary of the Treasury and the Secretary of Health and Human Services lifting designations of national economic turmoil and public health emergency, respectively. (4) Pro rata amounts The pro rata amount for each partial universal emergency rebate period shall be calculated by multiplying the monthly amount for a full universal emergency rebate that would be paid to the beneficiary based on household size for such a period by the percentage calculated by dividing the number of days of the partial universal emergency rebate