California state income tax applies to residents on their worldwide income at nine progressive rates running from 1% to 12.3%, with an additional 1% surcharge on taxable income above $1 million that lifts the top effective rate to 13.3%. Returns for the 2025 tax year are due April 15, 2026, and the state grants an automatic six-month extension to file, but any tax owed is still due in April.
Rates and Brackets for 2025
California uses a progressive system, so each slice of your taxable income is taxed at that slice’s rate. Moving into a higher bracket doesn’t raise the rate on the income below it. For single filers in the 2025 tax year:
- 1% on the first $11,079
- 2% from $11,079 to $26,264
- 4% from $26,264 to $41,452
- 6% from $41,452 to $57,542
- 8% from $57,542 to $72,724
- 9.3% from $72,724 to $371,479
- 10.3% from $371,479 to $445,771
- 11.3% from $445,771 to $742,953
- 12.3% above $742,953
Married couples filing jointly see those thresholds roughly doubled: the 1% bracket covers the first $22,158, and the 12.3% rate begins above $1,485,906.1Franchise Tax Board. 2025 California Tax Rate Schedules Head of household thresholds fall between the single and joint schedules.
On top of the brackets, Revenue and Taxation Code Section 17043 adds a 1% surcharge on every dollar of taxable income above $1 million, regardless of filing status. The surcharge funds the state’s Mental Health Services Act.2Mental Health Services Oversight and Accountability Commission. Mental Health Services Act Combined with the top bracket, this gives California the highest effective marginal rate in the country at 13.3%.
Standard Deduction and Personal Exemption
California’s standard deduction is well below the federal figure. For 2025, it’s $5,706 for single filers and those married filing separately, and $11,412 for married couples filing jointly, surviving spouses, and heads of household. Because the bar is so much lower, itemizing on the state return pays off for more filers than it does federally.
The state also provides a personal exemption credit that reduces your tax directly rather than your income. For 2025, that credit is $153 per filer and $475 per dependent. Both amounts adjust with inflation each year.
Who California Treats as a Resident
Residency drives everything else. California defines a resident as anyone present in the state for other than a temporary or transitory purpose, plus anyone who is domiciled here but temporarily away.3New York Codes, Rules and Regulations. 18 CCR 17014 – Who Are Residents and Nonresidents Your domicile is the place you consider your permanent home and intend to return to after any absence.
When physical presence and domicile point in different directions, the Franchise Tax Board weighs connecting factors: where your primary residence sits, where your driver’s license and vehicle are registered, where you vote, where your bank accounts are held, and where your professional licenses are active. No single factor settles it, but the more ties you have in California, the stronger the case that you’re a resident.
If you moved into or out of California during the year and changed your permanent domicile, you’re a part-year resident. You owe California tax on your worldwide income only for the months you lived in the state, plus any California-source income from the rest of the year.
Worldwide Income and the Other State Tax Credit
Full-year California residents owe state income tax on every dollar of taxable income, no matter where it was earned or deposited. Wages from a remote job based in another state, rent from an out-of-state property, gains in a foreign brokerage account — all of it goes on the California return.4California Legislative Information. California Revenue and Taxation Code 17041 The FTB also receives data from the IRS and from other states, so unreported income tends to surface eventually.
That reach creates obvious double-taxation problems. If you pay New York state tax on consulting income earned there, California still expects to see that income on your return. The Other State Tax Credit offsets the resulting California liability by the tax you already paid to the other state on the same income.5California Franchise Tax Board. Other State Tax Credit The credit is capped at the lesser of what you paid the other state or what California would have charged on that income. If the other state’s rate is lower, you’ll still owe California the difference. You claim the credit on Schedule S and attach a copy of the other state’s return.
Forms and Schedule CA Adjustments
Most full-year residents file Form 540. If your situation is simple (W-2 income, no itemized deductions, no adjustments), you may qualify for Form 540 2EZ. Part-year residents and nonresidents with California-source income file Form 540NR.6Franchise Tax Board. What Form You Should File
Every California return starts with your federal adjusted gross income from your 1040. Schedule CA then adjusts that figure for the many areas where California and federal law diverge:7Franchise Tax Board. 2025 Instructions for Schedule CA (540) California Adjustments
- California does not allow a deduction for state income tax, State Disability Insurance, or local general sales tax. If you itemize federally and took that deduction, add it back on Schedule CA.
- Mortgage interest follows California’s older limits: $1 million of acquisition debt ($500,000 if married filing separately), versus the current federal cap of $750,000 ($375,000 if married filing separately). Your state deduction can be larger.
- For tax years 2025 through 2029, up to $20,000 of military retirement pay or Survivor Benefit Plan annuity payments is excluded from California gross income.
- A 529 plan rollover to a Roth IRA that is tax-free federally is taxable in California and carries an additional 2.5% penalty.
- Through the end of 2026, California has suspended the net operating loss carryover deduction for taxpayers with net business income or modified AGI of $1 million or more.
Because of these adjustments, your California taxable income can look meaningfully different from your federal taxable income on the same raw earnings. Most of the complexity in a California return lives on Schedule CA.
Refundable Credits Worth Checking
The California Earned Income Tax Credit (CalEITC) is fully refundable for workers with earned income of $32,900 or less, with the amount scaling by the number of qualifying children. It covers workers aged 18 and up, including those 65 and older.8Franchise Tax Board. Eligibility and Credit Information CalEITC Families who qualify for CalEITC and have at least one child under six can also claim the Young Child Tax Credit, worth up to $1,189 for 2025. You must file a return to receive either credit, even if your income is otherwise below the filing requirement.
Deadline, Extension, and How to Pay
California personal income tax returns for 2025 are due April 15, 2026, matching the federal deadline.9Franchise Tax Board. Due Dates – Personal An automatic six-month extension pushes the filing deadline to October 15 with no form required.
The extension is only for paperwork. It is not an extension to pay. If you owe tax and don’t pay by April 15, penalties and interest start accruing on the unpaid balance even if you file the return on time in October.10Franchise Tax Board. Extension to File This catches people every year.
The FTB offers free electronic filing through CalFile, its direct e-filing system, which confirms receipt instantly.11Franchise Tax Board. CalFile Commercial tax software that supports California returns is another option, and paper returns still work, though they take longer. For payments, the FTB’s Web Pay portal handles direct bank transfers. Credit card payments go through third-party processors and carry convenience fees. Paying electronically by April 15 is the cleanest way to stop the penalty clock before it starts.
Estimated Payments if You Don’t Have Withholding
If you have income the IRS and FTB don’t see through withholding (self-employment, rentals, significant investment gains), you likely need to make quarterly estimated payments to California. The requirement applies when you expect to owe at least $500 for the year ($250 if married filing separately) and your withholding plus credits won’t cover at least 90% of the current year’s tax or 100% of the prior year’s tax, whichever is smaller.12Franchise Tax Board. Estimated Tax Payments
California’s payment schedule is lopsided in a way the federal schedule is not:
- April 15: 30% of estimated annual tax
- June 15: 40% of estimated annual tax
- September 15: no payment due
- January 15 of the following year: 30% of estimated annual tax
Seventy percent is due by mid-June, and nothing is due in September. If your prior-year adjusted gross income exceeded $150,000 ($75,000 if married filing separately), the safe harbor rises to 110% of last year’s tax. If your current-year income reaches $1 million or more ($500,000 if married filing separately), the prior-year safe harbor goes away entirely and payments must be based on 90% of the current year’s tax.12Franchise Tax Board. Estimated Tax Payments
Penalties and Interest
California charges separate penalties for filing late and paying late, and both can apply at once.
The late filing penalty, when a return is filed after the deadline (including any extension) without reasonable cause, is 5% of the unpaid tax for each month or partial month the return is late, capped at 25%. If the return is more than 60 days late, the minimum penalty is the lesser of $135 or 100% of the tax due.13California Legislative Information. California Revenue and Taxation Code 19131
The late payment penalty, when you file on time but don’t pay the full amount, is 5% of the unpaid tax as a one-time charge plus 0.5% for each month the balance remains unpaid, up to a combined 25%.14Franchise Tax Board. Common Penalties and Fees This is the trap behind the automatic extension: you file in October thinking you’re clear, but the payment penalty has been accumulating since April.
On top of penalties, the FTB charges interest on any unpaid balance. The rate adjusts twice a year; from July 2025 through June 2026, it’s 7% on personal income tax underpayments.15Franchise Tax Board. Interest and Estimate Penalty Rates Interest compounds daily and runs from the original due date until the balance is paid in full, regardless of any filing extension.
Keep copies of your return and supporting documents for at least four years. The FTB generally has four years from the filing date to assess additional tax, with the window extending to six years if you underreport gross income by more than 25%, and no time limit at all if you never file or file fraudulently.