Iowa current-year income tax returns are due on April 30 of the following year. When filing on paper, we use the postmark date to determine if a return is filed on time. When e-filing, the transmittal date is used.
If April 30 falls on a Saturday or Sunday, the due date is the following Monday.
Due Date(s) of Returns: The final return and any tax owing is due by the last day of the fourth month following the close of the tax year. Individuals may be required to remit estimated tax payments quarterly.
Income tax is also collected through withholding tax. Depending on the amount of tax withheld, withholding tax deposits are due annually, quarterly, monthly, or semi-monthly.