09/04/2026
Cousins...Being even one day late with a partnership or S corporation return can be more expensive than many business owners realize.
For returns required to be filed in 2026, the IRS late-filing penalty is generally $255 for each partner or shareholder for every month, or part of a month, that the return remains late, for up to 12 months. The penalty may not apply when the business establishes reasonable cause, and certain qualifying small partnerships may have specific penalty relief available.
Consider a partnership with four partners. If its return is filed even one day into the first late month, the basic penalty calculation can be $255 multiplied by four partners, or $1,020. That is why “only a few days late” should never be treated casually.
One common misunderstanding is that a partnership or S corporation filing deadline is less important because these entities generally pass income, deductions, credits, and other tax items through to their owners.
But pass-through treatment does not remove the entity’s federal filing responsibility. The business return also provides information used to prepare Schedule K-1s, which owners generally need for their own tax reporting.
If you received a valid extension for a calendar-year 2025 Form 1065 or Form 1120-S, September 15, 2026, is generally the extended filing deadline.
Now is the time to confirm that your CPA has everything needed to finish the return. Check for unanswered document requests, incomplete bookkeeping, missing transaction details, and unresolved questions.
If you believe your business cannot file on time, speak with your tax professional before assuming there is nothing you can do. If a penalty has already been assessed, professional review may also help determine whether reasonable-cause or other available relief applies.
A filing deadline is a financial responsibility. Please treat it accordingly, Cousin, starting right now, please.
If you need assistance, please contact our office at 757-977-8911 or email us at [email protected]
Dr. Lilly Mbinglo, CPA
I serve through Regent University as an Accounting Professor and through The Ark NPS as Founder and CPA, helping individuals, businesses, and nonprofits with accounting, tax, and business services.
