2025 California State Tax Deadlines
California Individual income tax filing deadlines and extensions for 2025.
If you are a resident or have been involved in business operations within California, you might be required to file California State taxes. California maintains one of the highest individual income tax rates in the nation, with rates ranging from 1% to 13.3%, plus an additional 1% Mental Health Services Tax on income over $1 million. This comprehensive guide outlines the key tax deadlines and considerations applicable to California in 2025.
California business tax deadlines for 2025
C Corporation deadlines and requirements
C Corporations in California must file and pay Corporate Income Taxes by April 15, 2026.
Filing requirements include:
- Complete Form 100 (California Corporation Franchise or Income Tax Return)
- File online with CalFile or through approved tax software
- File by mail must be postmarked by the due date
- Payment must be made by April 15, 2026
- A minimum franchise tax of $800 is required annually
Extension to file taxes in California for 2025
The Extension Deadline for California corporate income tax returns is November 15, 2026. California automatically grants a seven-month extension on filing corporate income tax returns without requiring separate forms. This is an extension to FILE, not an extension to PAY—payment is still due April 15, 2026.
Pass-through entities
California S Corporation and Partnership tax deadlines for 2025
S Corporations and Partnerships must file in California by March 15, 2026.
Required forms include:
- Form 100S – S Corporation Franchise or Income Tax Return
- Form 565 – Partnership Return of Income
Extension to file S Corporation and Partnership taxes in California for 2025
The Extension Deadline for California S Corporations returns is September 15, 2026, while Partnerships receive an extension until November 15, 2026. California automatically grants these extensions without requiring separate applications. This is an extension to FILE, not an extension to PAY—payment is still due March 15, 2026.
California individual tax considerations for 2025
Filing requirements and income thresholds
California Individuals must file a State income tax return if their gross income exceeds specific thresholds based on filing status.
The 2025 filing thresholds are:
- $14,725 for single taxpayers
- $29,450 for married filing jointly
- $22,088 for head of household filers
- $14,725 for married filing separately
Estimated tax deadline for California 2025
Estimated tax payments are due:
- April 15, 2025
- June 16, 2025
- September 15, 2025
- January 15, 2026
Who must make estimated payments
You must make California estimated income tax payments during 2025 if you expect to owe $500 or more in California income tax after subtracting your withholding and credits. Individuals with business income, rental properties, or investment gains typically need to make quarterly payments.
Individual tax deadline for California 2025
You must file and pay Individual Income Taxes in California by April 15, 2026. California accepts electronic filing through CalFile and other approved software platforms, significantly reducing processing time.
Available forms include:
- Form 540 – California Resident Income Tax Return
- Form 540NR – California Nonresident or Part-Year Resident Income Tax Return
Extension to file taxes in California for 2025
The Extension Deadline is October 15, 2026, to file your California Individual Income tax return. California automatically grants a six-month extension on filing personal income taxes without requiring separate State extension forms. This is an extension to FILE, not an extension to PAY—payment is still due April 15, 2026.
Wildfire disaster relief extensions for California 2025
Federal and State wildfire relief
Due to devastating wildfires that began on January 7, 2025, in Los Angeles County, the IRS and California Franchise Tax Board granted disaster relief extensions. Affected Individuals and businesses have until October 15, 2025, to file various federal and State tax returns originally due between January 7 and October 15, 2025.
Qualifying disaster areas
Los Angeles County taxpayers are eligible for extended deadlines, with additional counties potentially being added based on FEMA disaster declarations. The relief covers individual income taxes, corporate returns, estimated payments, and various business filings.
What California tax professionals need to know
Several key considerations make California's tax landscape unique for 2025:
California's high individual income tax rates create significant planning opportunities for wealthy taxpayers. The State offers various tax credits, including credits for research and development activities and film production incentives.
Electronic filing requirements
California encourages electronic filing for most taxpayers:
- C Corporations must file electronically for returns showing tax liability over $20,000
- Partnerships with more than 100 partners must file electronically
- Individuals can use CalFile for free electronic filing
How does California determine residency
California uses a facts-and-circumstances test to determine residency, considering factors like time spent in the State, location of family and business interests, and voter registration. Full-year residents pay tax on worldwide income, while part-year residents and nonresidents have different obligations.
California's unique tax features for 2025
Mental Health Services Tax
California imposes an additional 1% Mental Health Services Tax on taxable income exceeding $1 million for Individuals, resulting in a top marginal rate of 14.3% for high earners.
C Corporation minimum franchise tax
C Corporations must pay a minimum franchise tax of $800 annually, even if they have no income or operate at a loss. This tax is due on the 15th day of the fourth month after the beginning of the tax year.
LLC fee structure
Limited Liability Companies face both the $800 minimum franchise tax and additional fees based on total income from California sources, ranging from $900 to $11,790 annually for LLCs with gross receipts over $250,000.
Sources
- California Franchise Tax Board Due Dates
- IRS California Wildfire Relief
- California Individual Income Tax Information
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The material discussed on this page is meant for general illustration and/or informational purposes only and is not to be construed as investment, tax, or legal advice. You must exercise your own independent professional judgment, recognizing that advice should not be based on unreasonable factual or legal assumptions or unreasonably rely upon representations of the client or others. Further, any advice you provide in connection with tax return preparation must comply in full with the requirements of IRS Circular 230.
Please note that if any due date falls on a federal or state holiday or weekend, it may be adjusted to the next business day. Always verify current deadlines with the appropriate tax professional and authorities.
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