Form 1120‑S is the U.S. Income Tax Return for an S‑Corporation, a pass-through entity where profits and losses flow directly to shareholders. While S‑Corporations generally don’t pay federal income tax, they must still file an informational return with the IRS every year. This guide details the due dates for Form 1120‑S, how to request extensions using Form 7004, and how to coordinate federal and state deadlines efficiently.
📆 Standard Filing Due Date for Form 1120‑S
S‑Corporations operating on a calendar year must file Form 1120‑S by March 15 of the following year. This ensures that shareholders receive their Schedule K‑1s in time to include pass-through items on their personal returns. For example:
- For the 2024 tax year, the filing deadline is March 17, 2025 (since March 15 is a Saturday).
- Filing on time ensures partners avoid downstream delays on Form 1040 filings.
📅 Fiscal Year S‑Corporations
If your S‑Corporation operates on a fiscal year basis, the filing deadline is the 15th day of the third month following the close of the fiscal year. Example:
- If your fiscal year ends June 30, 2025, Form 1120‑S is due by September 15, 2025.
📝 How to File for an Extension Using Form 7004
Form 7004 allows S‑Corporations to request a six-month extension to file Form 1120‑S. However, it does not extend the time to issue K‑1s to shareholders or to pay any taxes due on behalf of certain elections or penalties.
- Form 7004 must be filed by the original due date — March 15 for calendar-year filers.
- If accepted, the new extended deadline becomes September 15 for calendar-year filers.
- Form 7004 can be filed electronically for faster confirmation.
📤 Sending Schedule K‑1s to Shareholders
Each shareholder must receive a Schedule K‑1 by the original or extended due date of Form 1120‑S. The K‑1 details each shareholder’s share of income, deductions, and credits, and failure to issue K‑1s timely may result in penalties for the corporation.
- Issue K‑1s no later than the Form 1120‑S deadline (including any extension).
- Document delivery via mail or secure digital transmission.
🛑 IRS Penalties for Late Filing
The IRS imposes stiff penalties if you fail to file Form 1120‑S on time or do not issue K‑1s by the deadline:
- $220 per shareholder per month for up to 12 months (2025 rate; subject to inflation).
- Penalties begin accruing from the original deadline, not the extension deadline.
- Form 7004 does not excuse late K‑1s if shareholders are not notified accordingly.
🏛️ State Tax Filing Synchronization
Many states require separate filings for S‑Corporations. Some conform closely to the federal March 15 deadline, while others follow their own schedules. Here’s a summary of common state scenarios:
- California: Form 100S is due March 15; $800 minimum franchise tax applies regardless of income.
- New York: Form CT‑3‑S due March 15; electronic filing is required for most filers.
- Texas: No individual income tax, but a Franchise Tax Report may be due May 15.
- Florida: S‑Corporations generally don’t file unless subject to corporate tax on federal taxable income.
🧩 Tips for Managing Federal and State Compliance Together
- Use tax software that auto-syncs both federal and state deadlines for consistency.
- Mark separate deadlines for state franchise taxes, which often differ from federal.
- Monitor S‑Corporation elections (Form 2553) if your business recently transitioned to S‑status.
- Keep records of both Form 7004 and K‑1 issuance dates in case of IRS or state audit.
📌 Extension and Deadline Summary Table
| Corporation Type | Tax Year End | Original Due Date | Extended Deadline (via Form 7004) |
|---|---|---|---|
| Calendar-Year S‑Corp | December 31 | March 15, 2025 | September 15, 2025 |
| Fiscal-Year S‑Corp | June 30, 2025 | September 15, 2025 | March 16, 2026 |
🧠 Final Thoughts
Form 1120‑S is a critical filing for S‑Corporations, especially when it comes to timely distribution of Schedule K‑1s. Understanding the filing deadlines — and proactively filing Form 7004 when needed — can help avoid costly penalties. Additionally, aligning your federal filing with state compliance, especially in jurisdictions like California and New York, ensures smooth and penalty-free operations across all levels of taxation.
