1. Short title This Act may be cited as the Small Business Assistance Act of 2020 . 2. Tax credit to small businesses to cover rent and mortgage payments (a) Allowance of credit (1) In general In the case of an eligible small business, there shall be allowed as a credit against the tax imposed by chapter 1 of the Internal Revenue Code of 1986 for the first taxable year beginning on or after January 1, 2019, an amount equal to the sum of any qualified rent or mortgage expenditures which— (A) relate to any real property which is primarily used in a trade or business of such eligible small business which is a qualified trade or business (as defined in section 199A(d)), and (B) are paid or incurred by such eligible small business during the first 4 months of 2020. (2) Limitation The amount of the credit allowable to a taxpayer under paragraph (1) for any taxable year shall not exceed $50,000. (b) Eligible small business For purposes of this section— (1) In general The term eligible small business means, with respect to calendar year 2019, an employer who has employed an average of not greater than 500 full-time employees on business days during such calendar year. (2) Application of aggregation rule for employers All persons treated as a single employer under subsection (b), (c), (m), or (o) of section 414 of the Internal Revenue Code of 1986 shall be treated as 1 employer. (c) Qualified rent or mortgage expenditures For purposes of this section, the term qualified rent or mortgage expenditures means an expenditure for rent or mortgage payments (not including any amounts attributable to utilities) that are paid pursuant to a contract entered into before the date of the enactment of this Act. (d) Expedited amended return process In the case of any eligible small business which has timely filed an amendment to the tax return for such business for the taxable year described in subsection (a) for the sole purpose of claiming the credit allowed under this section, the Secretary of the Treasury (or the Secretary's