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Montana Business State Tax Extension I LLCs / Partnerships Filing Guide

Form-PR | Montana Partnership Tax Payment Voucher  ·  LLCs / Partnerships  ·  Business Filing Guide

Overview

Montana LLCs and partnerships are subject to state tax filing requirements, administered by the Montana Department of Revenue. Montana automatically grants an extension to file with no application or form submission required.

Original Filing Deadline

The original due date for the Montana LLCs / Partnerships return is March 16, 2026. File or remit full payment by this date to remain in good standing.

Extension Granted Automatically

Montana automatically grants a filing extension for LLCs / Partnerships. The extended filing deadline is September 15, 2026. No application or form submission is required to receive this extension.

Payment Is Still Due by Original Deadline

The extension applies to filing only—it is not an extension to pay taxes owed. Any outstanding tax liability must be paid by the original due date of March 16, 2026 to avoid penalties and interest. Use the Montana | Online Tax Extension Payment to pay electronically. For mail-in payments, use Form-PR | Montana Partnership Tax Payment Voucher and send to: Montana Department of Revenue PO Box 8021 Helena, MT 59604-8021

Late Filing and Payment Penalties

• Failure to File: Lesser of $50 or tax due.
• Failure to Pay: 1.2% a month or fraction of a month on the unpaid tax, up to 12%.

Best Practices

• Estimate and pay your Montana business tax by March 16, 2026 to avoid interest and penalties.
• No extension form is required—Montana grants the extension automatically.
• Use the state online payment portal for fast, convenient electronic payment.
• Set a reminder to file your completed Montana LLCs / Partnerships return by September 15, 2026.

Final Thoughts

• Montana’s automatic extension simplifies the process—no paperwork required. Pay any balance due by March 16, 2026 and file your return by September 15, 2026.
• Quick Reference Table
• State Abbreviation
• MT
• State Name
• Montana
• Business Entity Type
• LLCs / Partnerships
• Extension Status
• Approved Automatically
• Return Due Date
• March 16, 2026
• Extended Due Date
• September 15, 2026
• Other Information
• Montana grants you an automatic 6-month extension to file your business tax return. The extension is NOT an extension to pay any taxes you may have due. Tax payments are due by the original return due date.
• Online Payment
• Montana | Online Tax Extension Payment
• Payment Voucher Form
• Form-PR | Montana Partnership Tax Payment Voucher
• State Payment Agency
• Montana Department of Revenue
• Mailing Address with Payment
• Montana Department of Revenue PO Box 8021 Helena, MT 59604-8021
• Failure to File Penalties
• Lesser of $50 or tax due.
• Failure to Pay Penalties
• 1.2% a month or fraction of a month on the unpaid tax, up to 12%.

Working with a Tax Professional

Business tax returns are complex—a licensed CPA or Enrolled Agent can maximize deductions, ensure accurate calculations, and handle filing on your behalf. Here's how working with a TaxPro typically goes:

1. 1Get matched with a verified U.S.-based CPA or Enrolled Agent
2. 2Upload your business documents via secure drag-and-drop
3. 3Review and approve your return with upfront, transparent fees
4. 4Your TaxPro files your Montana return by September 15, 2026

Quick Reference Table

State Abbreviation	MT
State Name	Montana
Business Entity Type	LLCs / Partnerships
Extension Status	Approved Automatically
Return Due Date	March 16, 2026
Extended Due Date	September 15, 2026
Other Information	Montana grants you an automatic 6-month extension to file your business tax return. The extension is NOT an extension to pay any taxes you may have due. Tax payments are due by the original return due date.
Online Payment	Montana | Online Tax Extension Payment
Payment Voucher Form	Form-PR | Montana Partnership Tax Payment Voucher
State Payment Agency	Montana Department of Revenue
Mailing Address with Payment	Montana Department of Revenue PO Box 8021 Helena, MT 59604-8021
Failure to File Penalties	Lesser of $50 or tax due.
Failure to Pay Penalties	1.2% a month or fraction of a month on the unpaid tax, up to 12%.