of only 1 spouse is included on the return of tax for the taxable year, and (ii) zero if the valid identification number of neither spouse is so included. (C) Valid identification number For purposes of this paragraph, the term valid identification number means a social security number issued to an individual by the Social Security Administration on or before the due date for filing the return for the taxable year. (D) Special rule for members of the Armed Forces Subparagraph (B) shall not apply in the case where at least 1 spouse was a member of the Armed Forces of the United States at any time during the taxable year and the valid identification number of at least 1 spouse is included on the return of tax for the taxable year. (E) Coordination with certain advance payments In the case of any payment determined pursuant to subsection (f)(6), a valid identification number shall be treated for purposes of this paragraph as included on the taxpayer’s return of tax if such valid identification number is available to the Secretary as described in such subsection. (F) Mathematical or clerical error authority Any omission of a correct valid identification number required under this paragraph shall be treated as a mathematical or clerical error for purposes of applying section 6213(g)(2) to such omission. (3) Credit treated as refundable The credit allowed by subsection (a) shall be treated as allowed by subpart C of part IV of subchapter A of chapter 1. (e) Regulations The Secretary shall prescribe such regulations or other guidance as may be necessary or appropriate to carry out the purposes of this section. (f) Outreach The Secretary shall carry out a robust and comprehensive outreach program to ensure that all taxpayers learn of their eligibility for the credits allowed under this section and are provided assistance in claiming such credits. . (b) Treatment of certain possessions (1) Payments to possessions with mirror code tax systems The Secretary of the Treasury shall pay to each possession of the United States