LLC Tax Filing Deadlines 2026: Complete Calendar

Published: February 28, 2026 | 7 min read | Tax Compliance

Missing an LLC tax deadline can cost you thousands in penalties and interest. Don't let that happen. Here's your complete 2026 calendar with every federal and state deadline you need to know.

2026 Federal LLC Tax Deadlines at a Glance

Understanding Your LLC's Tax Classification

Your LLC's tax deadlines depend on how it's taxed. Single-member LLCs default to sole proprietorship treatment, multi-member LLCs default to partnerships, but either can elect corporate taxation.

Quarterly Estimated Tax Deadlines 2026

If your LLC doesn't have taxes withheld (most don't), you'll likely need to pay quarterly estimated taxes. These cover both income tax and self-employment tax.

State LLC Tax Deadlines

State requirements vary significantly. Some states have income tax, others have franchise tax, and some have annual report fees. Here are common state obligations:

Annual Report/Biennial Report

• Delaware: June 1 (annual for LLCs)
• California: By end of anniversary month (annual)
• New York: End of anniversary month (biennial)
• Texas: May 15 (annual, no state income tax but franchise tax)
• Florida: May 1 (annual, no state income tax but annual report)

State Income/Franchise Tax

• Typically due same time as federal return or April 15
• Some states require separate extensions
• California has minimum $800 franchise tax regardless of income
• New York requires publication requirement within 120 days of formation

Penalties for Missing Deadlines

Federal Penalties

• Late filing: 5% of unpaid tax per month, up to 25%
• Late payment: 0.5% of unpaid tax per month, up to 25%
• Underpayment of estimated tax: Interest rate + 3% (varies quarterly)
• Late S-Corp/Partnership return: $210 per month per owner (up to 12 months)

Example Penalty Calculation

S-Corp with 2 owners filing 3 months late: $210 × 2 owners × 3 months = $1,260 penalty

That's a costly mistake for missing a deadline. File on time or request an extension.

How to File for an Extension

Partnerships & S-Corps (Form 7004)

• Automatic 6-month extension to September 15
• Must file by original March 16 deadline
• Doesn't extend time to pay taxes owed

C-Corps & Sole Props (Form 4868/7004)

• Automatic 6-month extension to October 15
• Sole props use Form 4868, C-Corps use Form 7004
• Must estimate and pay any taxes owed

Year-Round Planning Tips

January-February

• Review prior year income and expenses
• Organize receipts and documentation
• Schedule meeting with tax professional
• Pay Q4 estimated tax (January 15)

March

• File partnership/S-Corp returns by March 16
• Distribute Schedule K-1s to owners/partners
• Request extension if needed

April

• File C-Corp/Sole Prop returns by April 15
• Pay Q1 estimated tax
• File state returns

May-September

• Pay Q2 estimated tax (June 15)
• Pay Q3 estimated tax (September 15)
• File extended partnership/S-Corp returns
• Submit annual reports to state

October-December

• File extended C-Corp/Sole Prop returns (October 15)
• Begin year-end tax planning
• Review estimated tax payments vs. actual income
• Make final estimated tax adjustment

Common Questions

What if I can't pay the taxes I owe?

File on time anyway. The failure-to-file penalty (5%/month) is much higher than the failure-to-pay penalty (0.5%/month). You can set up a payment plan with the IRS.

Do I need to file if my LLC had no income?

Depends on your tax classification and state. S-Corps and partnerships generally must file regardless. Some states require annual reports even with zero activity. Check your specific requirements.

Can I change my LLC's tax classification?

Yes. File Form 8832 to change to C-Corp taxation, or Form 2553 for S-Corp status. Deadline restrictions apply. Generally, you can only make one change every 60 months.

What's the difference between fiscal year and calendar year?

Most LLCs use calendar year (Jan 1 - Dec 31). C-Corps can use fiscal years (any 12-month period). If you want to use a fiscal year, you must get IRS approval.

Related Articles

• LLC vs S-Corp: Which Tax Classification Saves More?
• LLC Formation Timeline: How Long Does It Really Take?
• Single-Member LLC vs Sole Proprietorship: Complete Comparison
• LLC State Requirements: A 50-State Comparison