California Business Tax Extension LLC / Partnership – S Corporation – C Corporation – Fiduciary / Estate / Trust
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Connect with a TaxPro →California Business Tax Extension – LLC / Partnership
FTB 3537 • LLC / PartnershipCalifornia LLC & Partnership Tax Extension
California LLCs and partnerships file with the California Franchise Tax Board (FTB). California is one of the few states that grants an automatic 6-month extension with no federal extension required – your California LLC return is automatically extended to September 15, 2026 without any additional filing.
How the Extension Works
California automatically grants a 6-month filing extension to LLCs and partnerships without requiring any application or federal extension. The original due date shifts to March 16, 2026 because March 15 is a Sunday. If you owe a California LLC fee or estimated tax, use FTB Form 3537 to remit payment by March 16, 2026. File the completed return by September 15, 2026.
Best Practices
- Note the March 16, 2026 original deadline – California's due date shifts one day because March 15 is a Sunday.
- Pay any California LLC fee and estimated tax by March 16, 2026 using FTB Form 3537.
- No extension application is needed – California's 6-month extension applies automatically.
- Pay electronically at the California FTB payment portal for immediate confirmation.
Working with a Tax Professional
LLC / Partnership returns carry unique complexities – a licensed CPA or Enrolled Agent can navigate the details and ensure your California return is filed accurately and on time.
- Get matched with a verified U.S.-based CPA or Enrolled Agent
- Upload your business documents via secure drag-and-drop
- Review your return with transparent, upfront pricing
- Your TaxPro files the California return by September 15, 2026
How to Pay
California requires online payment for tax amounts of $750 or more. Submit electronically via the California Online Tax Extension Payment portal. For amounts under $750, complete FTB 3537 and mail with your payment.
California Online Payment Portal
Submit electronically through the California Online Tax Extension Payment system. Required for all payments $750 and above.
FTB 3537 by Check
Download FTB 3537 and mail with your check or money order. Include your EIN and tax year on the check.
P.O. Box 942857
Sacramento, CA 94257-0531
Late Filing & Payment Penalties
| Penalty Type | Amount |
|---|---|
| Failure to File | 5% of the unpaid tax per month or fraction thereof, up to 25% |
| Failure to Pay | 5% of the unpaid tax per month or fraction thereof, up to 25% |
LLC / Partnership Quick Reference
| State Abbreviation | CA |
| Entity Type | LLC / Partnership |
| Extension Status | Automatic — no federal extension required |
| Original Filing Deadline | March 16, 2026 |
| Extended Filing Deadline | September 15, 2026 |
| Payment Due | March 16, 2026 (100% of tax owed) |
| Payment Form | FTB 3537 |
| Online Payment | California Online Tax Extension Payment |
| State Agency | California Franchise Tax Board |
| Failure to File Penalty | 5% of the unpaid tax per month or fraction thereof, up to 25% |
| Failure to Pay Penalty | 5% of the unpaid tax per month or fraction thereof, up to 25% |
California Business Tax Extension – S Corporation
FTB 3539 • S CorporationCalifornia S Corporation Tax Extension
California S Corporations file with the California Franchise Tax Board (FTB). California's extension is fully automatic – no federal extension or state application is needed. The California S Corporation return is extended to September 15, 2026 by default.
How the Extension Works
California automatically extends S Corporation filing deadlines – no filing is required to receive the extension. The original due date is March 16, 2026 (one day later than usual because March 15 falls on a Sunday in 2026). Use FTB Form 3539 to submit any California S Corporation tax balance by March 16, 2026. File the completed return by September 15, 2026.
Best Practices
- Pay the California S Corporation franchise tax by March 16, 2026 using FTB Form 3539.
- Confirm you have paid the $800 minimum franchise tax in addition to any income-based liability.
- No extension application is needed – California's 6-month extension is automatic.
- File the completed California S Corporation return no later than September 15, 2026.
Working with a Tax Professional
S Corporation returns carry unique complexities – a licensed CPA or Enrolled Agent can navigate the details and ensure your California return is filed accurately and on time.
- Get matched with a verified U.S.-based CPA or Enrolled Agent
- Upload your business documents via secure drag-and-drop
- Review your return with transparent, upfront pricing
- Your TaxPro files the California return by September 15, 2026
How to Pay
California requires online payment for tax amounts of $750 or more. Submit electronically via the California Online Tax Extension Payment portal. For amounts under $750, complete FTB 3539 and mail with your payment.
California Online Payment Portal
Submit electronically through the California Online Tax Extension Payment system. Required for all payments $750 and above.
FTB 3539 by Check
Download FTB 3539 and mail with your check or money order. Include your EIN and tax year on the check.
P.O. Box 942857
Sacramento, CA 94257-0531
Late Filing & Payment Penalties
| Penalty Type | Amount |
|---|---|
| Failure to File | 5% of the unpaid tax per month or fraction thereof, up to 25% |
| Failure to Pay | 5% of the unpaid tax per month or fraction thereof, up to 25% |
S Corporation Quick Reference
| State Abbreviation | CA |
| Entity Type | S Corporation |
| Extension Status | Automatic — no federal extension required |
| Original Filing Deadline | March 16, 2026 |
| Extended Filing Deadline | September 15, 2026 |
| Payment Due | March 16, 2026 (100% of tax owed) |
| Payment Form | FTB 3539 |
| Online Payment | California Online Tax Extension Payment |
| State Agency | California Franchise Tax Board |
| Failure to File Penalty | 5% of the unpaid tax per month or fraction thereof, up to 25% |
| Failure to Pay Penalty | 5% of the unpaid tax per month or fraction thereof, up to 25% |
California Business Tax Extension – C Corporation
FTB 3539 • C CorporationCalifornia C Corporation Tax Extension
California C Corporations are subject to the state franchise or income tax and file with the California Franchise Tax Board (FTB). California grants a 6-month automatic extension – no federal extension or application is needed to extend your state filing deadline to October 15, 2026.
How the Extension Works
California C Corporations benefit from a fully automatic 6-month extension – no paperwork is required to activate it. If your corporation owes California franchise or income tax, pay using FTB Form 3539 by April 15, 2026. The completed California C Corporation return is then due by October 15, 2026.
Best Practices
- Submit any California C Corporation tax balance using FTB Form 3539 by April 15, 2026.
- Verify you have covered the $800 minimum franchise tax in addition to any income-based liability.
- No extension filing is needed – California's 6-month extension applies automatically.
- Pay online at the FTB payment portal and retain your confirmation for your records.
Working with a Tax Professional
C Corporation returns carry unique complexities – a licensed CPA or Enrolled Agent can navigate the details and ensure your California return is filed accurately and on time.
- Get matched with a verified U.S.-based CPA or Enrolled Agent
- Upload your business documents via secure drag-and-drop
- Review your return with transparent, upfront pricing
- Your TaxPro files the California return by October 15, 2026
How to Pay
California requires online payment for tax amounts of $750 or more. Submit electronically via the California Online Tax Extension Payment portal. For amounts under $750, complete FTB 3539 and mail with your payment.
California Online Payment Portal
Submit electronically through the California Online Tax Extension Payment system. Required for all payments $750 and above.
FTB 3539 by Check
Download FTB 3539 and mail with your check or money order. Include your EIN and tax year on the check.
P.O. Box 942857
Sacramento, CA 94257-0531
Late Filing & Payment Penalties
| Penalty Type | Amount |
|---|---|
| Failure to File | 5% of the unpaid tax per month or fraction thereof, up to 25% |
| Failure to Pay | 5% of the unpaid tax per month or fraction thereof, up to 25% |
C Corporation Quick Reference
| State Abbreviation | CA |
| Entity Type | C Corporation |
| Extension Status | Automatic — no federal extension required |
| Original Filing Deadline | April 15, 2026 |
| Extended Filing Deadline | October 15, 2026 |
| Payment Due | April 15, 2026 (100% of tax owed) |
| Payment Form | FTB 3539 |
| Online Payment | California Online Tax Extension Payment |
| State Agency | California Franchise Tax Board |
| Failure to File Penalty | 5% of the unpaid tax per month or fraction thereof, up to 25% |
| Failure to Pay Penalty | 5% of the unpaid tax per month or fraction thereof, up to 25% |
California Business Tax Extension – Fiduciary / Estate / Trust
FTB 3539 • Fiduciary / Estate / TrustCalifornia Fiduciary Tax Extension
California estates and trusts with California-source income file with the California Franchise Tax Board (FTB). California automatically provides a 6-month extension for fiduciary returns – no application or federal extension is required to extend to October 15, 2026.
How the Extension Works
California fiduciary returns are automatically extended 6 months – giving estates and trusts until October 15, 2026 to file. If any California income tax is owed by the estate or trust, use FTB Form 3563 to remit payment by April 15, 2026. No separate extension form needs to be filed with the FTB.
Best Practices
- Pay any California fiduciary tax owed using FTB Form 3563 by April 15, 2026.
- No extension application is required – California's 6-month extension is fully automatic.
- Use the FTB online payment portal for fast, secure payment with electronic confirmation.
- File the completed California fiduciary return by October 15, 2026.
Working with a Tax Professional
Fiduciary / Estate / Trust returns carry unique complexities – a licensed CPA or Enrolled Agent can navigate the details and ensure your California return is filed accurately and on time.
- Get matched with a verified U.S.-based CPA or Enrolled Agent
- Upload your business documents via secure drag-and-drop
- Review your return with transparent, upfront pricing
- Your TaxPro files the California return by October 15, 2026
How to Pay
California requires online payment for tax amounts of $750 or more. Submit electronically via the California Online Tax Extension Payment portal. For amounts under $750, complete FTB 3539 and mail with your payment.
California Online Payment Portal
Submit electronically through the California Online Tax Extension Payment system. Required for all payments $750 and above.
FTB 3539 by Check
Download FTB 3539 and mail with your check or money order. Include your EIN and tax year on the check.
P.O. Box 942857
Sacramento, CA 94257-0531
Late Filing & Payment Penalties
| Penalty Type | Amount |
|---|---|
| Failure to File | 5% of the unpaid tax per month or fraction thereof, up to 25% |
| Failure to Pay | 5% of the unpaid tax per month or fraction thereof, up to 25% |
Fiduciary / Estate / Trust Quick Reference
| State Abbreviation | CA |
| Entity Type | Fiduciary / Estate / Trust |
| Extension Status | Automatic — no federal extension required |
| Original Filing Deadline | April 15, 2026 |
| Extended Filing Deadline | October 15, 2026 |
| Payment Due | April 15, 2026 (100% of tax owed) |
| Payment Form | FTB 3539 |
| Online Payment | California Online Tax Extension Payment |
| State Agency | California Franchise Tax Board |
| Failure to File Penalty | 5% of the unpaid tax per month or fraction thereof, up to 25% |
| Failure to Pay Penalty | 5% of the unpaid tax per month or fraction thereof, up to 25% |
Extended? Your California Business Return Deadline Is Coming Up.
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