Business Tax Deadlines

State filing information

Montana

Business tax filing in Montana: state returns, sales tax, other business taxes, and the federal dates that apply everywhere.

checked 2026-09-01Verified against Montana Department of Revenue. 11 sources.

Corporate income tax return

May 15
15th day of the 5th month after the close of the tax year

Partnership / S corporation returns

March 15
Partnerships March 15; Same for S corporations

Sales tax return

None
No statewide sales tax.

Other business taxes

2 taxes
Corporate income tax minimum tax ($50); Selective sales/use taxes (lodging facility use tax + lodging sales tax, rental vehicle tax, cannabis tax) and local resort taxes

Montana Department of Revenue

Other business taxes

TaxWho owes itDue
Corporate income tax minimum tax ($50)Every C corporation filing Form CITWith Form CIT, 15th day of the 5th month after year end (May 15 calendar year)
Selective sales/use taxes (lodging facility use tax + lodging sales tax, rental vehicle tax, cannabis tax) and local resort taxesOnly lodging, short-term vehicle rental, cannabis, and businesses in designated resort communities; not a general business tax–

Rules in full

Corporate income tax

15th day of the 5th month after the close of the tax year

Extension. Automatic 6-month extension to the 15th day of the 11th month after year end (Nov 15 for calendar year); payment still due by original due date

Partnerships and S corporations

Elective pass-through entity tax (SB 554, 2023) made annually on Form PTE by the extended due date; irrevocable once made. Rate 6.75% for 2023, 5.9% for 2024 and later. Quarterly PTET estimates due 15th of the 4th, 6th, 9th months and 1st month after year end (Apr 15/Jun 15/Sep 15/Jan 15); underpayment penalty and interest apply beginning tax year 2024. Composite tax and pass-through withholding are due on the original return due date regardless of extension.

Notes

Montana has no general sales tax and no franchise tax. PTET rate dropped from 6.75% (2023) to 5.9% (2024+).

What we could not confirm. Selective-tax due dates (lodging/rental vehicle) were not fetched from an official page and are left null. Annual report is a Secretary of State filing (not DOR) so it is null by design. The 2025 Form CIT instructions PDF could not be parsed; the CIT facts come from the DOR corporate-income-tax web page instead.

Minimum wage in Montana

State minimum wage

$10.85
Since January 1, 2026

Next change

Indexed adjustment January 1, 2027, amount TBA
Consumer Price Index, August of preceding year to August of current year... · adjusts January 1 annually

Tipped and local

Tipped cash wage $10.85
No local ordinances found

Checked 2026-09-02 against Montana Department of Labor & Industry, Employment Standards Division (Mont). All scheduled minimum wage increases.

Federal dates that apply in Montana

  1. NOV2Mon
    Employers (Payroll)
    FUTA deposit, Q3 2026 (if liability exceeds $500)
  2. NOV2Mon
    Employers (Payroll)
    Form 941, Q3 2026 (employer's quarterly return)
  3. NOV16Mon
    Tax-Exempt Organizations
    Form 990 extended return (Form 8868), tax year 2025
  4. DEC15Tue
    C-Corporations
    Q4 2026 corporate estimated tax (Form 1120-W)
  5. JAN15Fri
    Individuals & Sole Proprietors
    Q4 2026 estimated tax payment (Form 1040-ES)
  6. FEB1Mon
    Employers (Payroll)
    FUTA deposit, Q4 2026 (if liability exceeds $500)

All 2026 federal deadlines

Sources

  1. https://revenue.mt.gov/ official
  2. https://revenue.mt.gov/taxes/corporate-income-tax official
  3. https://revenue.mt.gov/publications/montana-corporate-income-tax-return-form-cit official
  4. https://revenue.mt.gov/taxes/pass-through-entities/s-corporations official
  5. https://revenue.mt.gov/taxes/pass-through-entities/partnerships official
  6. https://revenue.mt.gov/taxes/pass-through-entities/pass-through-entity-tax official
  7. https://www.forvismazars.us/forsights/2023/11/montana-issues-additional-guidance-on-pass-through-entity-tax-election official
  8. https://revenue.mt.gov/taxes/general-sales-tax official
  9. https://www.filelater.com/montana/business-extension-instructions/
  10. https://www.salestaxinstitute.com/jurisdiction/montana
  11. https://taxcloud.com/sales-tax/montana/

Checked 2026-09-01; researcher confidence 0.90. Corrections with a link to the state's own page: contact@businesstaxdeadlines.com.