Arizona Business Tax Extension 2026: 2025 Tax-Year Filing Guide
LLC & Partnership · S Corporation · C Corporation · Fiduciary
This guide explains how to file an Arizona (AZ) business tax extension for each entity type. For federal filing details, see our IRS Form 7004 business tax extension guide. Partnerships and S corporations generally receive six months, C corporations receive seven months, and fiduciaries generally receive five and a half months. Arizona tax is still due by the original deadline.
Need a pro? Connect with a U.S.-based CPA or EA to prepare and file your Arizona business return.
Remember, payment is still due by the original deadline. In other words, extensions only extend filing time.
Arizona (AZ) rules depend on entity type. Next, confirm the entity’s classification, file the required extension or retain federal proof when applicable, and pay required tax by the original deadline.
Arizona LLC Tax Extension: Filing Details
A calendar-year partnership or LLC taxed as a partnership generally files Form 165, as applicable, when an Arizona filing obligation applies. For the 2025 calendar-year return, the extended filing deadline is September 15, 2026.
In addition, the extension applies to filing time only. Therefore, pay required Arizona tax by the original deadline to limit penalties and interest.
The extension applies to filing time only. Pay required Arizona tax by the original deadline to limit penalties and interest.
Arizona S Corporation Tax Extension: Filing Details
For an S corporation, a calendar-year business generally files Form 120S when it has an Arizona filing obligation. For the 2025 calendar-year return, the extended filing deadline is September 15, 2026.
Arizona C Corporation Tax Extension: Filing Details
For a C corporation, a calendar-year business generally files Form 120 or Form 120A and must follow Arizona corporate-income-tax extension rules. For the 2025 calendar-year return, the extended filing deadline is November 16, 2026.
The extension applies to filing time only. Pay required Arizona tax by the original deadline to limit penalties and interest.
The extension applies to filing time only. Pay required Arizona tax by the original deadline to limit penalties and interest.
Fiduciary, Estate, and Trust Filing Details
Finally, a calendar-year estate or trust generally files Form 141AZ when it has an Arizona fiduciary filing obligation. For the 2025 calendar-year return, the extended filing deadline is September 30, 2026.
Quick Reference: Deadlines and Forms
The table below provides a quick reference to Arizona business tax extensions.
| Entity Type | AZ Return Form | Extension Method | Extended Deadline |
|---|---|---|---|
| LLC / Partnership | Form 165 | Federal six-month extension; Form 120/165 EXT | Sept. 15, 2026 |
| S Corporation | Form 120S | Form 120/165 EXT | Sept. 15, 2026 |
| C Corporation | Form 120 or Form 120A | Form 120/165 EXT | Nov. 16, 2026 |
| Fiduciary / Estate / Trust | Form 141AZ | Form 141AZ EXT | Sept. 30, 2026 |
Frequently Asked Questions
Quick answers about Arizona business tax extensions – but always confirm the current rules with the Arizona Department of Revenue.
Visit AZ DORYes. However, the applicable entity-specific requirements listed above must be satisfied. Arizona grants extensions to LLCs, partnerships, S corporations, C corporations, and fiduciaries, but the rules – including which form to file, how long the extension lasts, and the payment threshold – vary by entity type. If you need an individual rather than business extension, see our Arizona individual tax extension page.
Generally no. In other words, pay required tax by the original deadline and confirm the current state payment rules. An extension of time to file does not extend the time to pay – failing to pay by the original deadline can result in penalties and interest, even if the return is filed within the extended window.
No. In practice, partnerships, S corporations, C corporations, and fiduciaries can use different original dates, extension periods, or forms. For 2025 calendar-year returns filed in 2026, partnerships and S corporations generally get a six-month extension (Sept. 15), C corporations get a seven-month extension (Nov. 16), and fiduciaries get a five-and-a-half-month extension (Sept. 30).
Review the Arizona Department of Revenue guidance for the entity’s return. Additionally, the DOR publishes the most current forms (Form 120/165 EXT and Form 141AZ EXT.) and any changes to extension periods or payment thresholds.
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