Avoid IRS Penalties: March 16th Deadline for 2025 S Corporation & Partnership Tax Returns
Don’t Miss the March 16th Business Tax Filing Deadline
For S corporations and partnerships operating on a calendar year, March 16, 2026, is the deadline to file your 2025 business tax return. While this filing date doesn’t require you to make a tax payment, missing it can still lead to costly penalties—even when no tax is due.
Understanding the Late-Filing Penalty
The IRS calculates the penalty based on two factors: how many months the return is late and the number of shareholders or partners. For 2025 returns, the penalty is $255 per month, per shareholder or partner, up to 12 months.*
That means a married couple who jointly own an S corporation could face a $525 penalty for filing just one day late. Yes—even if the business owes nothing.
How to Protect Yourself From Penalties
1. File on Time
If you’re a partner or S corporation shareholder, make sure your business return is filed by March 16th. Filing late doesn’t just trigger penalties—it also shortens the time you have to complete your individual tax return and pay any taxes owed by April 15th.
2. Consider Filing an Extension
If your business return won’t be ready by the deadline, submit an extension by March 16th. This gives you an additional six months—but remember, the extension only applies to filing, not paying. Taxes for flow‑through businesses are still due with your Form 1040 on April 15th.
3. Expect Potential Delays for Your Personal Return
Your individual tax return depends on receiving all Form K‑1s from your S corporation or partnership activities. If your business files an extension, your personal return may also need one. Be prepared to estimate your 2025 tax liability and make a payment by April 15th to avoid interest or penalties.
4. Challenge the Penalty If Necessary
If you do receive a late‑filing penalty, you may be able to request IRS penalty abatement. This is especially reasonable when your personal taxes were filed and paid on time. It never hurts to remind the IRS that the U.S. Treasury is receiving the taxes owed promptly.
Need Help Meeting the Deadline?
If you haven't yet filed your 2025 S corporation or partnership tax return, there’s still time to take action. Our team at Cohn, Lopez & Associates can help you file on time, request an extension, or navigate IRS notices with confidence.
Contact us if you need support—we’re here to help you stay compliant and avoid unnecessary penalties.
*Penalty calculation for 2025 S corporations and partnerships: $255 per shareholder or partner for each month or part of a month the return is late, up to 12 months.