The following penalties apply to Iowa sales and use, withholding and income taxes.

• 10% Penalty for Failure to Timely File a Return:
  If you do not file your return by the due date and at least 90% of the correct tax is not paid, you owe an additional 10% of the unpaid tax.
• 5% Penalty for Failure to Timely Pay the Tax Due:
  If you file your return on time but do not pay at least 90% of the correct tax due, you owe an additional 5% of the unpaid tax.

You will never be subject to both penalties.

This summary is based on Rule 421.27.

Information on waiver of penalties