Montana Business Tax Deadlines (2026)
Next: June 15, 2026 — Federal & Montana Q2 Estimated Tax Payment
Next Deadline: June 15, 2026 — Federal & Montana Q2 Estimated Tax Payment
Federal Tax Deadlines (2026)
| Form | Who Files | Due Date | Extension Deadline |
|---|---|---|---|
| Form 1040 (Schedule C) | Sole proprietors | April 15 | October 15 |
| Form 1065 | Partnerships, Multi-member LLCs | March 15 | September 15 |
| Form 1120-S | S-Corporations | March 15 | September 15 |
| Form 1120 | C-Corporations | April 15 | October 15 |
| Form 990 | Nonprofits | May 15 | November 15 |
| Estimated Taxes (Q1) | All | April 15 | — |
| Estimated Taxes (Q2) | All | June 15 | — |
| Estimated Taxes (Q3) | All | September 15 | — |
| Estimated Taxes (Q4) | All | January 15, 2027 | — |
Montana State Tax Deadlines (2026)
| Tax Type | Due Date | Form/Filing | Notes |
|---|---|---|---|
| Individual Income Tax | April 15 | Form 2 | Rates 4.7%–5.9% |
| Corporate Income Tax | May 15 | Form CIT | 6.75% rate; due 15th of 5th month |
| S-Corp Return | March 15 | Form CLT-4S | Pass-through |
| Partnership Return | March 15 | Form PR-1 | Pass-through |
| No Sales Tax | — | — | Montana has no general sales tax |
| Withholding Tax (Monthly/Quarterly) | Varies by payroll | Form MW-1 | Employers |
| Annual Report | April 15 | Filed with Secretary of State | $20 fee |
| Estimated Income Tax (Q1) | April 15 | Form ESA / CIT-ES | — |
| Estimated Income Tax (Q2) | June 15 | Form ESA / CIT-ES | — |
| Estimated Income Tax (Q3) | September 15 | Form ESA / CIT-ES | — |
| Estimated Income Tax (Q4) | January 15, 2027 | Form ESA / CIT-ES | — |
Quarterly Estimated Tax Deadlines in Montana
Montana follows the federal estimated tax payment schedule:
Estimated payments are required if you expect to owe $500 or more in Montana income tax.
Montana-Specific Tax Requirements
Montana has a graduated individual income tax with rates from 4.7% to 5.9% (recently simplified from a wider bracket system). The corporate income tax rate is 6.75%, and notably the corporate return is due on the 15th of the 5th month (May 15 for calendar-year filers), which is later than most states. There is no franchise tax or gross receipts tax.
Montana is one of five states with no general sales tax, making it popular for consumers and simplifying compliance for businesses. However, some resort communities levy a resort tax (up to 3%) on luxury items, food, beverages, and lodging. If your business operates in a resort area (Big Sky, West Yellowstone, Red Lodge, Whitefish, Virginia City), you'll need to collect and remit resort tax.
Montana requires annual reports filed with the Secretary of State by April 15 for a $20 fee. The state has relatively straightforward employer withholding requirements. Montana also imposes various industry-specific taxes including coal severance tax, oil and natural gas production tax, and metal mines tax. For most small businesses, the lack of sales tax and moderate income tax rates make Montana fairly business-friendly.
What Happens If You Miss a Montana Tax Deadline?
Montana Department of Revenue
Get Your Books Ready Before Tax Season
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