Disclaimer: This article is for general educational purposes and does not constitute tax advice. Tax outcomes depend on your specific facts and circumstances. Consult a licensed CPA before making filing decisions.
Updated July 2026: The original March 16, 2026 deadline has passed. If you filed Form 7004 on time, your extended S-Corp/partnership deadline is September 15, 2026 - do not wait until September to start. If you missed the deadline entirely, jump to "What Are My Options If I Missed the March 16 Deadline?" - penalties accrue monthly.
In This Article
- What Does the March 16, 2026 S-Corp and Partnership Tax Deadline Cover?
- How Does the March 16 Entity Deadline Affect an Owner's Individual Return?
- What Tax Forms Are Actually Due on March 16 for S-Corps and Partnerships?
- What New Jersey-Specific Requirements Apply to S-Corps and Partnerships on March 16?
- What Should I Do If I Can't File My S-Corp or Partnership Return by March 16?
- What Are the Late Filing Penalties for S-Corp and Partnership Returns?
- What Should S-Corp and Partnership Owners Do Before the March 16 Deadline?
- What Are My Options If I Missed the March 16 S-Corp or Partnership Deadline?
- Frequently Asked Questions
- Ready to File With Confidence?
What Does the March 16, 2026 S-Corp and Partnership Tax Deadline Cover?
For a calendar-year S corporation or partnership, March 16, 2026 is the original federal return due date for:
- Form 1120-S: the U.S. Income Tax Return for an S Corporation
- Form 1065: the U.S. Return of Partnership Income
- Schedule K-1s: which must be distributed to all shareholders (S-Corps) or partners (partnerships) by this same date
Note: March 15 is the statutory deadline, but it falls on a Sunday in 2026, so the actual deadline shifts to Monday, March 16, 2026.
How Does the March 16 Entity Deadline Affect an Owner's Individual Return?
An entity return and its Schedule K-1 information can affect when an owner has the information needed to complete an individual return.
Here's why: S-Corps and partnerships file informational returns and issue Schedule K-1s that report each owner's share of income, deductions, and credits. Your personal return (Form 1040) cannot be completed accurately until you receive your K-1. This means:
- If the entity return is late or incomplete, an owner may need an extension or later amendment depending on the information available and the individual-return facts.
- An owner may file Form 4868 when the individual return cannot be completed by its due date; an extension of time to file does not extend the time to pay.
- A late or corrected Schedule K-1 can require additional individual-return analysis and, in some cases, an amended return.
The entity deadline precedes the ordinary individual deadline, but the required filing and payment steps depend on each entity and owner return.
What Tax Forms Are Actually Due on March 16 for S-Corps and Partnerships?
Form 1120-S (S-Corporations)
Form 1120-S reports the S-Corporation's income, deductions, and credits for the year. The return itself generally does not result in a tax payment (S-Corps are pass-through entities; income is taxed at the shareholder level) - though an S-Corp can owe entity-level federal tax in specific situations, including the built-in gains tax, the excess net passive income tax, and LIFO recapture, as noted below. However, the return must be filed or extended on time, and Schedule K-1s must be distributed to all shareholders.
Key items on 1120-S:
- Ordinary business income or loss
- Rental income and other separately stated items
- Section 179 deductions and bonus depreciation
- Shareholder W-2 wages (reasonable compensation)
- Accumulated Adjustments Account (AAA)
Form 1065 (Partnerships and Multi-Member LLCs)
Form 1065 is the informational return for general partnerships, limited partnerships, LLPs, and multi-member LLCs taxed as partnerships. Like the 1120-S, the return generally produces no entity-level federal income tax - but a partnership can still owe amounts at the entity level, including an imputed underpayment under the BBA centralized partnership audit rules, Section 1446 withholding for foreign partners, and New Jersey BAIT if elected.
Key items on 1065:
- Ordinary income or loss from partnership activities
- Guaranteed payments to partners
- Section 704(b) allocations if partners have special allocation agreements
- Self-employment income allocations for general partners
Schedule K-1s
This is the document each owner receives from the entity. It shows your individual share of income, deductions, and credits. K-1s must be distributed by the same March 16 deadline.
If you have multiple K-1s (e.g., you're a partner in multiple partnerships or an investor in several S-Corps), all of them should be in your hands before you can finalize your personal return.
What New Jersey-Specific Requirements Apply to S-Corps and Partnerships on March 16?
New Jersey has its own pass-through entity requirements that align with (but are not identical to) federal due dates.
NJ-1065 (Partnerships)
New Jersey requires partnerships to file Form NJ-1065 by the 15th day of the 4th month following the close of the tax year - April 15, 2026 for calendar-year filers (NOT March 15/16; NJ-1065 is NOT on the federal partnership deadline). The NJ-1065 includes a New Jersey Gross Income Tax prepayment for non-resident partners. A federal Form 7004 that extends Form 1065 also provides a 5-month extension to file NJ-1065 when a copy is attached to the NJ return. If an NJ-1065 filing fee is due, file PART-200-T with the required payment by the original due date; if NJ-CBT-1065 tax is due, use CBT-206 under its separate payment rule. Form NJ-630 - the Gross Income Tax extension used for NJ-1040/NJ-1041 filings - is not used for partnerships.
NJ BAIT Election
The New Jersey Business Alternative Income Tax (BAIT) allows pass-through entities to elect to pay income tax at the entity level. The TY2025 BAIT election had to be made via the NJ Division of Taxation's PTE File and Pay System on or before March 16, 2026 - the original due date of the 2025 PTE-100 (the 15th day of the third month after the close of the tax year, rolled from Sunday March 15). For TY2026, the election must be made on or before March 15, 2027. The election is NOT made on the entity tax return. A qualifying entity-level payment may affect the owners' federal SALT-cap computation, but the result depends on the entity, owners, QBI, credits, and timing.
NJ CBT-100S (S-Corporations)
S-Corporations in New Jersey must file Form CBT-100S by the 15th day of the month following the federal due date - April 15, 2026 for TY2025 calendar-year filers (one month after the federal March 16, 2026 deadline). The 6-month extension is requested on Form CBT-200-T and extends the return to October 15, 2026. Unlike federal S-Corp treatment, where income generally passes through to shareholders although specified entity-level taxes can apply (for example IRC 1374 built-in gains tax, IRC 1375 excess net passive income tax, LIFO recapture, and investment-credit recapture), New Jersey imposes a tiered minimum CBT tax ($375 to $1,500 based on NJ gross receipts) and potentially additional CBT tax on S-Corps. Those receipts tiers are the standalone, non-QSSS schedule: a taxpayer that is a member of an affiliated group under IRC 1504 or a controlled group under IRC 1563 whose total payroll, measured group-wide rather than only in New Jersey, is $5,000,000 or more owes a $2,000 minimum regardless of gross receipts (N.J.S.A. 54:10A-5(e)), and a QSSS is consolidated onto its parent's CBT-100S and listed on Schedule Q with its own minimum tax remitted with the parent's payment. These NJ entity-level obligations must be computed separately from federal pass-through treatment.
NJ CBT-100 (C-Corporations)
NJ C-Corporations file Form CBT-100 by the 15th day of the 5th month after the close of the tax year - May 15, 2026 for TY2025 calendar-year filers (one month after the federal C-Corp April 15 deadline). The 6-month extension via Form CBT-200-T runs to November 16, 2026.
What Should I Do If I Can't File My S-Corp or Partnership Return by March 16?
File an extension. The IRS automatically grants a 6-month extension if you file Form 7004 by March 16. For S-Corps, this extends the deadline to September 15, 2026. For partnerships, the same: September 15, 2026.
Important: An extension of time to file is not an extension of time to pay. If your entity owes any taxes (some S-Corps owe built-in gains tax or excess net passive income tax), those amounts are still due by March 16. Underpayment can result in penalties and interest.
NJ extension: CBT-200-T is used for CBT-100S and CBT-100 extensions. For NJ-1065, a federal Form 7004 that extends Form 1065 also provides a 5-month filing extension when a copy is attached to the New Jersey return. If an NJ-1065 filing fee is due, file PART-200-T and pay at least 80% of the total fee reported when filed by the original due date. If NJ-CBT-1065 tax on nonresident partners is due, file CBT-206 and pay at least 90% of the total tax reported when filed by the original due date. Form NJ-630 applies to individual and fiduciary Gross Income Tax returns, not partnerships.
What Are the Late Filing Penalties for S-Corp and Partnership Returns?
The IRS imposes penalties for late filing of pass-through entity returns:
- Form 1065 (Partnerships): $255 per partner, per month (up to 12 months maximum) for TY2025 returns filed in 2026, per Rev. Proc. 2024-40 (Rev. Proc. 2025-32 raises this to $260 for returns filed in 2027). So a 3-partner LLC that files 3 months late could face $2,295 in penalties.
- Form 1120-S (S-Corps): $255 per shareholder, per month (up to 12 months maximum) for TY2025 returns filed in 2026.
These penalties can add up quickly for multi-partner arrangements. A timely, valid Form 7004 extension avoids the late-filing penalty only through the extended September 15 deadline and only if the return is actually filed by then - and it does not extend the time to pay any tax owed.
What Should S-Corp and Partnership Owners Do Before the March 16 Deadline?
If you own an S-Corp or partnership and have not yet engaged a CPA for your 2025 return, here's what to do right now:
- Gather your 2025 financials. P&L statement, balance sheet, and bank reconciliations for the full year.
- Compile payroll records. W-2s for all employees, including owner-employees (S-Corp shareholders who received wages).
- Pull last year's return. Your 2024 1120-S or 1065 provides carry-forward items, basis schedules, and depreciation records.
- Contact a CPA now. If March 16, 2026 has already passed and you filed Form 7004 on time, your extended deadline is September 15, 2026 - do not wait until September to start. If you missed the deadline without an extension, see the next section: penalties accrue monthly, so file as soon as possible.
For an existing eligible entity, use the written contact form to request a return-preparation scope; submission does not promise availability, engagement, response timing, or outcome.
What Are My Options If I Missed the March 16 S-Corp or Partnership Deadline?
If you missed the March 16 deadline and did not file Form 7004 on time, file the late S-Corp or partnership return as soon as possible because penalties accrue monthly. A late-filed Form 7004 does not grant an extension. Evaluate eligibility for first-time abatement or reasonable-cause relief, and remember that any tax owed was due on the original deadline.
If you missed the deadline, use the contact form to request a written scope for late-return preparation. Submitting it does not promise a call, engagement, or relief result.
Use the S-Corp Calculator only as a limited payroll-tax comparison; it does not determine whether an election makes sense for you. A complete return-wide model with fact-supported reasonable compensation is required, and no savings or result is promised.
Greg Monaco, CPA is the founder and sole practitioner of Gregory Monaco, CPA LLC, a virtual CPA practice based in Livingston, NJ. His New Jersey CPA license and firm registration are publicly verifiable.
Related reading: Tax Resources | Services | About Greg Monaco | Contact
Frequently Asked Questions
What happens if I miss the March 16 S-Corp or partnership deadline?
The IRS imposes a penalty of $255 per shareholder or partner per month, up to 12 months (TY2025 returns filed in 2026, per Rev. Proc. 2024-40). A 3-partner LLC that files 3 months late could face $2,295 in penalties. Filing Form 7004 before the deadline avoids the late-filing penalty only if the return is then filed by the extended September 15 due date - and payment of any tax owed is still due at the original deadline.
Does filing Form 7004 give me more time to pay taxes?
No. Form 7004 extends your time to file the return, not your time to pay. Any federal entity-level taxes (such as S-Corp built-in gains or excess net passive income tax) are still due by the original March 16 deadline. New Jersey CBT for S-Corps is due with the CBT-100S by its own April 15 due date - and a CBT-200-T extension extends only the filing, not the payment. Underpayment triggers penalties and interest.
Do I need to file a separate NJ extension for my S-Corp or partnership?
For NJ-1065, a federal Form 7004 that extends Form 1065 also provides a 5-month filing extension when a copy is attached to the New Jersey return. If an NJ-1065 filing fee is due, file PART-200-T and pay at least 80% of the total fee reported when filed by the original due date. If NJ-CBT-1065 tax on nonresident partners is due, file CBT-206 and pay at least 90% of the total tax reported when filed by the original due date. S-Corps use CBT-200-T. NJ partnership extensions are 5 months, not 6.
Can I still elect S-Corp status if I missed the March 15 deadline?
Potentially. The IRS allows late Form 2553 filings under Rev. Proc. 2013-30 if you had reasonable cause, intended S-Corp treatment from the effective date, and all shareholders reported income consistently with S-Corp status. The late filing must be within 3 years and 75 days of the intended effective date.
Ready to File With Confidence?
Tax rules change frequently. Use the contact form to request a written scope; submitting it does not promise a call, engagement, or outcome. Greg Monaco is a NJ-licensed CPA and the firm's sole practitioner.
