Coordination with advance refunds of credit

The amount of credit which would (but for this paragraph) be allowable under this section shall be reduced (but not below zero) by the aggregate refunds and credits made or allowed to the taxpayer under subsection (f). 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).

In the case of a refund or credit made or allowed under subsection (f) 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.