Iowa Code Title X. Financial Resources [Chs. 421-454] § 422.73. Correction of errors--refunds, credits, and carrybacks

2. a. If it appears that an amount of tax, penalty, or interest has been paid which was not due under subchapter II, III or V of this chapter, then that amount shall be credited against any tax due on the books of the department by the person who made the excessive payment, or that amount shall be refunded to the person or with the person's approval, credited to tax to become due. A claim for refund or credit that has not been filed with the department within three years after the return upon which a refund or credit claimed became due, or within one year after the payment of the tax upon which a refund or credit is claimed was made, whichever time is the later, shall not be allowed by the director. If, as a result of a carryback of a net operating loss or a net capital loss, the amount of tax in a prior period is reduced and an overpayment results, the claim for refund or credit of the overpayment shall be filed with the department within the three years after the return for the taxable year of the net operating loss or net capital loss became due.

b. Notwithstanding the period of limitation specified in paragraph “a”, the taxpayer shall have one year from the final determination date of any final federal adjustment arising from an internal revenue service audit or other similar action by the internal revenue service with respect to the particular tax year to claim an income tax refund or credit arising from that final federal adjustment.