; qualifying dependent For purposes of this section— (1) Qualifying child The term qualifying child means any qualifying dependent of the taxpayer— (A) who is a qualifying child (as defined in section 7706(c)) of the taxpayer, (B) who has not attained age 17 at the close of the calendar year in which the taxable year of the taxpayer begins, and (C) whose name and social security number are included on the taxpayer’s return of tax for the taxable year. (2) Qualifying dependent The term qualifying dependent means any dependent of the taxpayer (as defined in section 7706 without regard to all that follows resident of the United States in section 7706(b)(3)(A)) whose name and TIN are included on the taxpayer’s return of tax for the taxable year. (3) Social security number defined For purposes of this subsection, the term social security number means, with respect to a return of tax, a social security number issued to an individual by the Social Security Administration, but only if the social security number is issued— (A) to a citizen of the United States or pursuant to subclause (I) (or that portion of subclause (III) that relates to subclause (I)) of section 205(c)(2)(B)(i) of the Social Security Act, and (B) on or before the due date of filing such return. . (b) Portion of credit refundable (1) In general Section 24(d)(1)(A) is amended to read as follows: (A) the credit which would be allowed under this section determined— (i) by substituting $1,400 for $2,000 in subsection (a)(1), (ii) without regard to subsection (a)(2), and (iii) without regard to this subsection and the limitation under section 26(a), or . (2) Modification of limitation based on earned income Section 24(d)(1)(B)(i) is amended by striking $3,000 and inserting $2,500 . (3) Inflation adjustment Section 24(d) is amended by inserting after paragraph (3) the following new paragraph: (4) Adjustment for inflation (A) In general In the case of a taxable year beginning after 2018, the $1,400 amount in paragraph (1)(A)(i) shall be increased by an amount