According to the State of Arizona, returns should be filed no later than Friday, April 15, 2022. Because
April 15, 2022 falls on a federal holiday, you have until Monday, April 18, 2022 to timely file your 2021 tax return.
If an individual taxpayer needs to file an extension, please file Form 204 by April 18, 2022. Taxpayers are not required to file Form 204 if they already have a federal extension from the IRS.