An extension to file is not an extension to pay tax.
Arizona will honor a federal extension for the equivalent period, or grants its own extension on Form 204, provided at least 90% of the tax liability is paid by the original due date. Miss that 90% threshold and the extension underpayment penalty applies even though the paperwork was timely.
| Item | Detail |
|---|---|
| Form required | Form 204, unless a federal extension was filed and no Arizona Form 204 payment is being mailed (electronic federal extension payment substitutes) |
| Individual extension length | 6 months, to October 15, 2026 |
| Corporate extension length | Up to 7 months, to the following November 15 for calendar-year filers |
| Payment threshold | At least 90% of the tax liability for the period must be paid by the original due date; shortfall triggers the extension underpayment penalty of 0.5% per 30-day period |
| Authority | A.R.S. §42-1107 (extension of time for filing returns); A.R.S. §42-1125(D) (underpayment penalty) |