Tax season is here — and if you live or run a business in California, you have TWO sets of deadlines to track: the IRS (federal) and the California Franchise Tax Board, or FTB (state).
Miss one of them and you could face late penalties, interest charges, or worse. The good news? You’re reading this. Let’s break it all down in plain English so you know exactly when to file, when to pay, and when to ask for help.
What Are the Key 2026 Tax Deadlines for California?
Whether you’re an individual taxpayer or a business owner, here’s everything you need to know about the 2026 tax deadlines California residents and companies must follow.
Individual Tax Deadlines — Federal (IRS) & State (FTB)
April 15, 2026 — The Big One
This is the most important tax filing deadline April brings every year. It applies to:
- Individual federal income tax returns (Form 1040)
- Individual California state income tax returns (Form 540)
- Any taxes you owe — both federal and state — are due on this date, even if you file an extension
Important: An extension gives you more time to file, not more time to pay. If you owe money, you must still pay your estimated taxes by April 15 to avoid penalties.
October 15, 2026 — Extended Filing Deadline
If you filed for an extension by April 15, your final deadline to submit your return is October 15, 2026. This applies to both your IRS return and your California FTB return.
Quarterly Estimated Tax Deadlines — 2026
Self-employed individuals, freelancers, gig workers, and small business owners who don’t have taxes withheld from a paycheck must pay quarterly estimated taxes. Here are the 2026 dates:
| Payment | Covers Period | Due Date |
|---|---|---|
| Q1 | January – March | April 15, 2026 |
| Q2 | April – May | June 16, 2026 |
| Q3 | June – August | September 15, 2026 |
| Q4 | September – December | January 15, 2027 |
Missing these payments can trigger an underpayment penalty from the IRS — even if you pay everything by April. The California FTB follows a slightly different schedule (Q1 and Q2 are both due in April), so always confirm with a California tax professional.
Business Tax Deadline California — What Business Owners Need to Know
March 15, 2026 — S-Corps & Partnerships
If your business is structured as an S-Corporation or Partnership, your federal return is due on March 15, 2026 — a full month before the individual deadline. California follows the same date for state returns.
This is one of the most commonly missed business tax deadline California dates because many business owners assume it’s April 15.
April 15, 2026 — C-Corps & Sole Proprietors
C-Corporations file on April 15. Sole proprietors report business income on their personal tax return (Schedule C), also due April 15.
May 15, 2026 — Nonprofits
Tax-exempt organizations must file Form 990 by May 15.
California FTB Deadlines — What’s Different From the IRS?
The California Franchise Tax Board (FTB) runs its own filing system separate from the IRS. Here’s what makes it unique:
- California’s estimated tax schedule is different. Your Q1 and Q2 estimated payments are both due on April 15. Q3 is due June 15 and Q4 is due January 15.
- California has its own extension form. You don’t automatically get an extension just because you filed one with the IRS. California requires Form FTB 3519 if you owe state taxes.
- California LLC Annual Fee. If you own an LLC in California, you must pay a minimum $800 annual franchise tax — usually by April 15 for calendar-year LLCs.
- Disaster extensions. In years where FEMA declares a California disaster, the IRS and FTB often extend deadlines for affected counties. Always check for updates during tax season.
What Happens If You Miss a Deadline?
Missing the IRS deadline 2026 or a California FTB deadline can trigger:
- Late filing penalty: 5% of unpaid taxes per month (up to 25%)
- Late payment penalty: 0.5% per month
- Interest: Charged on top of unpaid amounts from the due date
- FTB penalties: California adds its own 5% late filing penalty
The sooner you file — even if you can’t pay everything right away — the less you’ll owe in penalties.
Don’t Wait — Here’s What You Should Do Right Now
- Gather your documents — W-2s, 1099s, receipts for deductions, prior year returns
- Check if you owe estimated taxes — especially if you’re self-employed
- Know your business entity deadlines — S-Corps and partnerships file before April 15
- Contact a California tax professional if your situation is complex — multiple income sources, business ownership, rental income, or if you received a notice from the IRS or FTB
Need Help Meeting Your 2026 Tax Deadlines?
At ABSE Tax, we’ve helped hundreds of individuals and businesses in Artesia and the greater Los Angeles area file on time, avoid penalties, and get the maximum refund they deserve.
Whether you need help with your personal return, business taxes, payroll, or staying on top of California FTB deadlines — our team is ready.
📞 Call us at 562-403-1177 📧 Email: info@absetax.com 📍 18000 Pioneer Blvd, Artesia, CA 90701
