If you received a refund of federal income tax during 2018:
You must report the amount on this line. It must be reported even if you used the standard deduction on the prior year's Iowa return. The federal refund must be included on this line because you benefited from being able to deduct federal taxes on the prior year's Iowa return, which reduced your Iowa taxable income for that year. The amount reported on this line should not exceed the total amount of any federal tax deduction taken on the prior year(s) Iowa return.
To find the amount you received, check your records or call the IRS at 1-800-829-1040. This information is not available from the Iowa Department of Revenue.
If you chose to have any part of an overpayment of federal income tax credited to estimated tax payments for 2018, the amount should be claimed as 2018 estimated tax paid on line 32. The total federal overpayment must also be reported on line 27.