New Hampshire Business Tax Extension 2026: 2025 Tax-Year Filing Guide
LLC & Partnership · S Corporation · C Corporation · Fiduciary
This guide explains how to file a New Hampshire (NH) business tax extension for each entity type. For example, New Hampshire taxpayers generally receive seven months, while partnerships generally receive seven months. 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 NH return.
Remember, payment is still due by the original deadline. In other words, extensions only extend filing time.
New Hampshire (NH) 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 Hampshire LLC Tax Extension: Filing Details
A calendar-year partnership or LLC taxed as a partnership generally files Forms NH-1065, as applicable, when a New Hampshire filing obligation applies. For the 2025 calendar-year return, the extended filing deadline is November 16, 2026.
In addition, the extension applies to filing time only. Therefore, pay required New Hampshire tax by the original deadline to limit penalties and interest.
The extension applies to filing time only. Pay required New Hampshire tax by the original deadline to limit penalties and interest.
New Hampshire S Corporation Tax Extension: Filing Details
For an S corporation, a calendar-year business generally files Form NH-1120 when it has a New Hampshire filing obligation. For the 2025 calendar-year return, the extended filing deadline is November 16, 2026.
New Hampshire C Corporation Tax Extension: Filing Details
For a C corporation, a calendar-year business generally files Form NH-1120 and must follow New Hampshire new hampshire 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 New Hampshire tax by the original deadline to limit penalties and interest.
The extension applies to filing time only. Pay required New Hampshire 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 NH-1041 when it has a New Hampshire fiduciary filing obligation. For the 2025 calendar-year return, the extended filing deadline is November 16, 2026.
Quick Reference: Deadlines and Forms
The table below provides a quick reference to New Hampshire business tax extensions. See our IRS Form 7004 guide, New Hampshire individual tax extension, and business tax extension resource for related guidance.
| Entity Type | NH Return Form | Extension Method | Extended Deadline |
|---|---|---|---|
| LLC / Partnership | NH-1065 | Federal extension;; BT-EXT | Oct. 15, 2026 |
| S Corporation | NH-1120 | BT-EXT | Nov. 16, 2026 |
| C Corporation | NH-1120 | BT-EXT | Nov. 16, 2026 |
| Fiduciary / Estate / Trust | NH-1041 | Form BT-EXT | Nov. 16, 2026 |
Frequently Asked Questions
Quick answers about New Hampshire business tax extensions – but always confirm the current rules with the New Hampshire Division of Taxation.
Visit NH DORYes. However, the applicable entity-specific requirements listed above must be satisfied. New Hampshire 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 seven-month extension (Sept. 15), while the others generally get a seven-month extension (Oct. 15).
Review the New Hampshire Division of Taxation guidance for the entity’s return. Additionally, the DOR publishes the most current forms (BT-EXT, BT-EXT, BT-EXT, etc.) and any changes to extension periods or payment thresholds.
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