New Mexico Business Tax Extension 2026: 2025 Tax-Year Filing Guide
LLC & Partnership · S Corporation · C Corporation · Fiduciary
This guide explains how to file a New Mexico (NM) business tax extension for each entity type. New Mexico generally honors a valid federal extension, while additional state time may require RPD-41096. However, estimated tax remains due by the original deadline.
Need a pro? Connect with a U.S.-based CPA or EA to prepare and file your New Mexico business return.
Remember, payment is still due by the original deadline. In other words, extensions only extend filing time.
New Mexico (NM) 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.
New Mexico LLC Tax Extension: Filing Details
A calendar-year partnership or LLC taxed as a partnership generally files Form PTE, when a New Mexico 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 New Mexico tax by the original deadline to limit penalties and interest.
The extension applies to filing time only. Pay required New Mexico tax by the original deadline to limit penalties and interest.
New Mexico S Corporation Tax Extension: Filing Details
For an S corporation, a calendar-year business generally files Form S-Corp when it has a New Mexico filing obligation. For the 2025 calendar-year return, the extended filing deadline is September 15, 2026.
New Mexico C Corporation Tax Extension: Filing Details
For a C corporation, a calendar-year business generally files Form CIT-1 and must follow New Mexico corporate-income-tax extension rules. For the 2025 calendar-year return, the extended filing deadline is October 15, 2026.
The extension applies to filing time only. Pay required New Mexico tax by the original deadline to limit penalties and interest.
The extension applies to filing time only. Pay required New Mexico 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 FID-1 when it has a New Mexico fiduciary filing obligation. For the 2025 calendar-year return, the extended filing deadline is October 15, 2026.
Quick Reference: Deadlines and Forms
The table below provides a quick reference to New Mexico business tax extensions. See our IRS Form 7004 guide, New Mexico individual tax extension, and business tax extension resource for related guidance.
| Entity Type | NM Return Form | Extension Method | Extended Deadline |
|---|---|---|---|
| LLC / Partnership | Form PTE | Federal Form 7004; RPD-41096 if needed | Sept. 15, 2026 |
| S Corporation | S-Corp | Federal Form 7004 | Sept. 15, 2026 |
| C Corporation | Form CIT-1 | Federal Form 7004 | Oct. 15, 2026 |
| Fiduciary / Estate / Trust | FID-1 | Form Federal Form 7004 | Oct. 15, 2026 |
Frequently Asked Questions
Quick answers about New Mexico business tax extensions – but always confirm the current rules with the New Mexico Taxation and Revenue Department.
Visit NM DORYes. However, the applicable entity-specific requirements listed above must be satisfied. New Mexico 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.
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 LLCs taxed as partnerships get a five-month extension (Sept. 15), while the others generally get a six-month extension (Oct. 15).
Review the New Mexico Taxation and Revenue Department guidance for the entity’s return. Additionally, the DOR publishes the most current forms (Federal Form 7004, RPD-41096, Federal Form 7004, etc.) and any changes to extension periods or payment thresholds.