701—40.20 (422) Adjustments to prior years. When Iowa requests for refunds are filed, they shall be allowed only if filed within three years after the tax payment upon which a refund or credit became due, or one year after the tax payment was made, whichever time is the later. Even though a refund may be barred by the statute of limitations, a loss shall be carried back and applied against income on a previous year to determine the correct amount of loss carryforward.
This rule is intended to implement Iowa Code section 422.73.