any taxable year which may be taken into account under subsection (a) shall not exceed $6,000. (2) Coordination with dependent care assistance exclusion The dollar amount in paragraph (1) shall be reduced by the aggregate amount excluded from gross income under section 129 for the taxable year, if any. (d) Special rules For purposes of this section— (1) Payments to related individuals No credit shall be allowed under subsection (a) for any amount paid to an individual with respect to whom, for the taxable year, a deduction under section 151(c) is allowable either to the taxpayer or the taxpayer's spouse. For purposes of this paragraph, the term taxable year means the taxable year of the taxpayer in which the service is performed. (2) Identifying information required with respect to service provider No credit shall be allowed under subsection (a) for any amount paid to any person unless— (A) the name, address, and taxpayer identification number of such person are included on the return claiming the credit, or (B) if such person is an organization described in section 501(c)(3) and exempt from tax under section 501(a), the name and address of such person are included on the return claiming the credit. In the case of a failure to provide the information required under the preceding sentence, the preceding sentence shall not apply if it is shown that the taxpayer exercised due diligence in attempting to provide the information so required. (3) Identifying information required with respect to qualifying individuals No credit shall be allowed under subsection (a) with respect to any qualifying individual unless the taxpayer identification number of such individual is included on the return claiming the credit. (e) Denial of double benefit No credit shall be allowed under subsection (a) for any amount with respect to which a credit is allowed under section 21. (f) Regulations The Secretary shall prescribe such regulations as may be necessary to carry out the purposes of this section. . (b) Clerical amendment The table