2027 Montana Tax Deadlines

Last updated: August 5, 2026

Key Montana tax dates at a glance

This block is the single date reference for 2027 Montana filing, payment, estimated-payment, and extension planning.

• March 15, 2028: Montana S Corporation and Partnership Form PTE returns and payments due for calendar-year filers.
• April 15, 2027: First Montana estimated Individual income tax payment due.
• June 15, 2027: Second Montana estimated Individual income tax payment due.
• September 15, 2027: Third Montana estimated Individual income tax payment due.
• January 18, 2028: Fourth Montana estimated Individual income tax payment due.
• April 18, 2028: Montana Individual Form 2 returns and balances due for calendar-year filers.
• May 15, 2028: Montana C Corporation Form CIT return and balance due for calendar-year filers.
• September 15, 2028: Extended Montana S Corporation and Partnership returns due; payment is not extended.
• October 16, 2028: Extended Montana Individual returns due; payment is not extended.
• November 15, 2028: Extended Montana C Corporation returns due; payment is not extended.

When are Montana taxes due in 2027?

Montana 2027 calendar-year S Corporation and Partnership returns are generally due March 15, 2028, Individual returns are due April 18, 2028, and C Corporation returns are due May 15, 2028. Estimated payments and filing-only extensions should be tracked separately by taxpayer type.

When are Montana C Corporation taxes due for 2027?

Montana C Corporations file Form CIT, Corporate Income Tax Return, and pay by May 15, 2028. Montana grants a six-month extension to November 15, 2028, but payment remains due May 15, 2028.

• Complete Form CIT, Corporate Income Tax Return.
• Use the Montana TransAction Portal (TAP) for eligible filing and payment.
• Pay the expected balance by May 15, 2028.
• Postmark permitted paper submissions by the due date.

When are Montana S Corporation and Partnership taxes due for 2027?

Montana S Corporations and Partnerships file Form PTE by March 15, 2028. Montana grants a six-month extension to September 15, 2028, but payment remains due March 15, 2028.

• Form PTE: Montana Pass-Through Entity Tax Return.

When are Montana Individual taxes due for 2027?

A Montana Individual return is due April 18, 2028. Form 2 filers and nonresident or part-year resident ratio schedule filers receive an extended filing deadline of October 16, 2028, but payment remains due April 18, 2028.

• Form 2: Montana Individual Income Tax Return.
• Form 2 with the Nonresident/Part-Year Resident Ratio Schedule, when applicable.

For 2027, Montana applies a 4.7% rate up to $65,000 of taxable income for single filers and $130,000 for married taxpayers filing jointly, with a 5.4% rate above the applicable threshold.

When are Montana estimated payments due?

Calendar-year Montana estimated payments are due on this schedule:

• April 15, 2027.
• June 15, 2027.
• September 15, 2027.
• January 18, 2028.

Who must make Montana estimated payments?

Taxpayers who expect a Montana income-tax balance after withholding and credits may need estimated payments. Apply the tax-year 2027 threshold, safe-harbor, and voucher instructions when the filing-year guidance is released.

What Montana rules should tax professionals watch for 2027?

• Montana is one of five states without a general sales tax and has no local sales tax complications, which changes compliance planning for retail, tourism, and local-tax review.
• Natural-resource items include coal severance tax, metalliferous mines license tax, resource extraction taxes, oil and gas production taxes, working-interest depletion allowances, enhanced recovery incentives, pipelines, and reclamation or environmental bonds.
• Agriculture and ranch operations may involve agricultural land assessments, beginning farmer and rancher programs, livestock tax items, agricultural equipment exemptions, drought relief, and disaster relief.
• Business incentives include Big Sky Economic Development Trust Fund, Microbusiness Finance Program, Research and Development Credit, qualifying industry investment incentives, and rural development programs.
• Tourism, resort and accommodation taxes, outfitter and guide licensing, forestry and timber taxes, renewable energy, hydroelectric, coal, natural gas, and retirement-income items should be checked against current Montana instructions.

Tax-professional context: Several considerations make Montana's tax landscape distinctive for 2027. Montana now applies a two-rate individual income tax — 4.7% up to the applicable threshold and 5.4% above it — alongside a May 15 C Corporation due date that differs from the federal calendar. The state remains one of a few with no general sales tax and offers incentives tied to natural resources, agriculture, energy, and tourism. Electronic filing through the Montana TransAction Portal (TAP) continues to expand, with Form CIT and Form PTE anchoring corporate and pass-through filing.

Electronic filing requirements:

• C Corporations and pass-through entities should file electronically through Montana TAP when eligible.
• Individuals can use Montana's online system for free electronic filing when they qualify.
• Business deductions, portal confirmations, and payment evidence should stay attached to the return record.
• Professional preparers should use approved software vendors and retain electronic submission confirmations.

Business Tax Credits:

• Big Sky Economic Development Trust Fund
• Microbusiness Finance Program
• Research and Development Credit
• Investment incentives for qualifying industries
• Rural development programs

No sales tax advantage:

• Montana has no general sales tax, which can lower consumer tax burden and simplify some retail compliance.
• The no-sales-tax environment can be attractive for retail and tourism businesses.
• Tax teams should still check resort, accommodation, industry, local, and special tax obligations.
• No general sales tax does not remove Montana income-tax, pass-through, natural-resource, or property-related obligations.

Natural-resource / industry details:

• Mining and minerals items include coal severance tax provisions, metalliferous mines license tax, resource extraction taxes, and reclamation or environmental bonds.
• Oil and gas items include production taxes, working-interest depletion allowances, enhanced recovery incentives, pipeline considerations, and transportation considerations.
• Tourism and recreation items include resort and accommodation tax provisions, outfitter and guide licensing, recreation equipment sales tax exemptions, and seasonal business planning.
• Forestry and timber items include timber yield tax provisions, forest land taxation programs, sustainable forestry incentives, and fire prevention or suppression considerations.
• Energy items include wind and solar incentives, hydroelectric generation, coal and natural gas production, and alternative-energy research credits.

Retirement income considerations:

• Military retirement pay exemptions may apply.
• Social Security benefits are generally exempt from Montana state income tax.
• Pension income considerations for residents.
• Senior citizen property-tax benefits.

Montana's move to Form CIT and its no-sales-tax profile shift planning priorities so that firms can find specialists through the accounting firm directory.

What sources support these Montana deadlines?

• Montana Department of Revenue.
• Montana Individual Income Tax.
• Montana Pass-Through Entities.

Montana filing deadlines for complex industries

Instead's AI-driven tax platform keeps Montana filing dates, payment evidence, and entity-specific review steps in one calendar, with filing workflows tied to the actual return work instead of a generic deadline tracker.

Use workflows and planning to keep Montana return work, no-sales-tax considerations, and payment evidence moving through reviewer-controlled workflows. Built for tax professionals who want a cleaner way to manage Montana deadlines, filings, and review.