Enterprise
Individual & Small Business
| Payment | Arizona due date |
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| 1 | |
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Federal 2026 estimated tax due dates, for comparison: April 15, 2026, June 15, 2026, September 15, 2026, January 15, 2027.
Who must pay Arizona estimated tax?
You must make Arizona estimated income tax payments during 2026 if your Arizona gross income for 2025 was greater than $75,000 (single, head of household, or married filing separately) or $150,000 (married filing joint) AND your Arizona gross income for 2026 exceeds the same amount. If you met the income threshold for 2025, you must make estimated payments during 2026 unless you are sure you will not meet the threshold for 2026.
How do you avoid a Arizona underpayment penalty?
Payments plus Arizona withholding must total either 90% of the tax due for 2026 or 100% of the tax due for 2025 (no 110% rule stated). Filing the 2026 return and paying in full by February 1, 2027 removes the 4th payment. Threshold is income-based (Arizona gross income > $75,000; $150,000 MFJ), not a tax-owed amount.
How much should you pay?
Start with your federal estimate: the free Quarterly Estimated Tax Calculator works out your 2026 federal payments and safe harbor. Arizona figures its own tax, so the state amount is separate.