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March 2026 Business Deadlines: Keeping Your Montana Business on Track

March is often a pivotal month here in Billings. We are looking forward to spring, but in the business world, we are deep in the trenches of tax season. For many of our service-based clients—especially our subcontractors and real estate professionals—this month brings some of the most critical deadlines of the year.

Keeping your business compliant is about more than just avoiding penalties; it’s about maintaining that “three-legged stool” of stability we always talk about: accurate books, optimized taxes, and timely payroll. When you hit these dates with confidence, you know your business is standing on solid ground.

Here are the key dates to mark on your calendar for March 2026.

March 2: The Paper Filing Deadline

While we generally encourage electronic filing for its speed and security, if your business still relies on paper forms for information returns, the clock runs out today.

Information Returns (Forms 1099)
If you are filing paper copies of Forms 1099 (excluding the 1099-NEC which was due in February) and the transmittal Form 1096 with the government, they must be sent by today.

ACA Reporting (ALE)
Applicable Large Employers (ALEs) filing paper Forms 1094-C and 1095-C must submit them to the IRS today. This also applies to other providers of minimum essential coverage filing paper Forms 1094-B and 1095-B.

Health Coverage to Employees
Regardless of how you file with the IRS, today is the deadline to provide Form 1095-C (for ALEs) or Form 1095-B (for other providers) directly to your employees or responsible individuals.

Farmers and Fishermen
For our clients in the agriculture sector across Montana, file your 2025 income tax return (Form 1040) and pay any tax due today. If you already paid your estimated tax by January 15, you have until April 15 to file.

Note: March 2 is also the paper filing deadline for Payers of Gambling Winnings (Form W-2G) and Large Food and Beverage Establishments (Form 8027).

Stressed business owner dealing with paperwork

March 16: Partnerships and S Corporations

For many of the businesses we serve earning between $100K and $500K, this is your primary tax deadline. This date is crucial for maintaining the integrity of your entity structure.

Partnerships (Form 1065)

File your 2025 calendar year return (Form 1065). You must provide each partner with their Schedule K-1 (and Schedule K-3 if applicable). If you need more time to ensure your books are accurate, filing Form 7004 gives you an automatic 6-month extension. Remember, an extension to file is not an extension to pay.

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S Corporations (Form 1120-S)

File your 2025 calendar year income tax return (Form 1120-S) and pay any tax due. Just like partnerships, you must provide each shareholder with their Schedule K-1. If you aren't ready to file, use Form 7004 to request a 6-month extension, but be sure to pay any estimated tax owed to avoid interest and penalties.

Small business owner working in a salon

S Corporation Election (Form 2553)

If you have been operating as a sole proprietorship or LLC and want to be taxed as an S Corp for the 2026 tax year, you must file Form 2553 by today. This is a common strategy we review with our clients to help optimize self-employment taxes. If you miss this date, the election generally won't take effect until 2027.

Payroll and Withholding

If you are on a monthly deposit schedule for Social Security, Medicare, and withheld income tax (or non-payroll withholding), deposit the tax for payments made in February by today.

March 31: Electronic Filing Deadline

If you file electronically—which is our standard practice for simplicity and efficiency—this is your final due date for several forms.

  • Forms 1099, 1098, and W-2G: Deadline for electronic filing with the IRS.
  • ACA Forms: Deadline for electronic filing of Forms 1094-C, 1095-C, 1094-B, and 1095-B.
  • Tip Income: Deadline for electronic filing of Form 8027.

Important Reminders

Weekends and Holidays: When a due date falls on a weekend or legal holiday, it shifts to the next business day.

Disaster Area Extensions: Given the unpredictable weather in our region and beyond, remember that designated disaster areas often receive automatic extensions. You can check the current status on the FEMA and IRS websites.

We build our firm on honesty and lasting relationships. If these dates are approaching and you are feeling unsure about your books or your tax position, don't wait.

Let’s ensure your three-legged stool is stable for the year ahead. Contact us today to discuss your filing requirements.

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