Montana business tax deadlines

Montana PTET Election (Form PTE)

Montana Pass-Through Entity Tax election deadline (with the entity return). PTET allows S-Corps and partnerships to pay state tax at the entity level, making it federally deductible. Most underutilized Montana planning opportunity.

Montana Individual & Business Returns

Form 2 (individual) and entity returns due, aligned with federal dates. Extension to October 15 available.

Montana Estimated Taxes

April 15, June 16, September 15, January 15 — same schedule as federal estimates.

Montana UI Tax (UI-5)

Quarterly state unemployment insurance returns due the last day of the month following the quarter.

Q4 Estimated Tax Payment

Final estimated tax payment for the prior tax year (individuals, sole props, S-Corp owners).

W-2s & 1099-NEC Due

W-2s to employees, 1099-NEC to contractors and the IRS, 941 for Q4 of prior year.

Paper 1099 Filings

Deadline for paper 1099 filings to the IRS (March 31 if filing electronically).

S-Corp & Partnership Returns

Form 1120-S (S-Corp) and Form 1065 (Partnership) due. Extension to September 15 available via Form 7004. Also: S-Corp election (Form 2553) deadline for current tax year.

Individual & C-Corp Returns + Q1 Estimated Tax

Form 1040 (individuals, sole props with Schedule C), Form 1120 (C-Corp), and Q1 estimated tax payment. Extension via Form 4868 (individuals) or Form 7004 (corps) — extends filing, NOT payment.

Q1 Form 941

Quarterly federal payroll tax return for the January–March quarter.

Q2 Estimated Tax

Second-quarter estimated tax payment for the current tax year.

Q2 Form 941

Quarterly federal payroll tax return for the April–June quarter.

Q3 Estimated Tax + Extended S-Corp/Partnership

Third-quarter estimated tax payment AND extended S-Corp and Partnership returns due.

Extended Individual & C-Corp Returns

Final deadline for extended Form 1040 and Form 1120 returns. No further extensions.

Q3 Form 941

Quarterly federal payroll tax return for the July–September quarter.

Year-End Planning Deadline

Last day for owner draws, retirement contributions to apply to current tax year, Section 179 equipment placed in service, and most year-end tax moves.