Arizona tax deadlines in 2026: filing dates and estimated payments
Deadlines that fall in calendar 2026: the 2025 return and the 2026 estimated payments. Different year? See Arizona 2025 →
Arizona deadlines in 2026
| 2025 individual return due | April 15, 2026 |
|---|---|
| Extended filing deadline | October 15, 2026 |
| Payment due | April 15, 2026, extension or not |
| Final 2025 estimated payment | January 15, 2026 |
| 2026 estimated payments | April 15, 2026 · June 15, 2026 · September 15, 2026 · January 15, 2027 |
Conforms to the federal deadline.
Arizona estimated tax payments in 2026
Your Arizona gross income exceeds $75,000 (single, married filing separately, head of household) or $150,000 (married filing jointly) for both the prior year and the current year.
| Q1 (2026 tax year) | April 15, 2026 |
|---|---|
| Q2 (2026 tax year) | June 15, 2026 |
| Q3 (2026 tax year) | September 15, 2026 |
| Q4 (2026 tax year) | January 15, 2027 |
| Voucher | Form 140ES |
| Underpayment safe harbor | Estimated payments plus Arizona withholding must total at least 90% of the tax due for the current year or 100% of the tax due for the prior year; no penalty or interest is assessed if the Arizona tax due on the return is less than $1,000. |
| Pay online | aztaxes.gov |
Four installments as printed in the 2026 Form 140ES booklet; Pay on AZTaxes.gov by selecting '140ES: Estimate Payments'; do not mail the voucher if paying online. Small Business Income filers use Form 140ES-SBI.
Source: azleg.gov and azdor.gov, read September 3, 2026.
All 51 jurisdictions in one table: state estimated tax payment dates for 2026.
Arizona extensions
Every state's rule in one table: which states accept the federal extension in 2026.
| Does Arizona accept the federal extension? | Only in some cases. See the rule below. |
|---|---|
| State extension form | Form 204 |
| Original due date | April 15, 2026 |
| Extended due date | October 15, 2026 |
| Payment | Still due April 15, 2026. The extension is to file, not to pay. The federal extension counts for Arizona only if at least 90% of the Arizona tax is paid by April 15, 2026; otherwise a penalty of one half of one percent per 30 days applies, up to 25%. |
| How to get it | File federal Form 4868 and pay at least 90% of your Arizona tax by April 15, 2026 (Form 204 or AZTaxes.gov for the payment); check the extension box on the Arizona return. File Form 204 for a state-only extension. |
A.R.S. 42-1107(B). The Department of Revenue site blocks automated reading, so the statute is cited.
Source: azleg.gov and azdor.gov, read September 3, 2026. “the taxpayer is deemed to have been granted the same extension of time for filing the Arizona income tax return if the taxpayer has paid at least ninety percent of the tax liability”
Federal deadlines in 2026
| 2025 Form 1040 | April 15, 2026 · extension October 15, 2026 |
|---|---|
| 2025 S-corp (1120-S) & partnership (1065) | March 16, 2026 |
| 2025 C-corp (Form 1120) | April 15, 2026 |
| 2026 federal estimated payments (1040-ES) | April 15, 2026 · June 15, 2026 · September 15, 2026 · January 15, 2027 |
Source: IRS Publication 509 and Form 1040-ES instructions, irs.gov.
Frequently asked questions
When are Arizona state taxes due in 2026?
Your 2025 Arizona individual income tax return is due April 15, 2026. If that date falls on a weekend or legal holiday, the deadline moves to the next business day. An extension moves the filing deadline to October 15, 2026, but any tax owed is still due on the original date.
When are Arizona estimated tax payments due in 2026?
Arizona estimated payments for the 2026 tax year are due April 15, 2026, June 15, 2026, September 15, 2026, January 15, 2027. Use Form 140ES or pay online. The final installment for 2025 was due January 15, 2026.
Does Arizona accept the federal extension?
Only in some cases. See the rule below. The state form is Form 204. The extended filing deadline is October 15, 2026, and tax is still due by April 15, 2026.
Does a Arizona extension give me more time to pay?
No. An extension extends the time to file, not to pay. To avoid penalties and interest, pay what you expect to owe by April 15, 2026.
Dates are the statutory deadlines that fall in 2026 and move to the next business day when they land on a weekend or holiday. Each section links to the source it was checked against. Always confirm with the Arizona tax agency or the IRS before relying on a date. This is general information, not tax advice.