The California C corp tax rate is a flat 8.84% of net income attributable to the state, or an $800 minimum franchise tax, whichever is greater. Every C corporation incorporated, registered, or doing business in California owes at least the $800 each year, even with no revenue. Banks and financial corporations pay 10.84% instead. Federal corporate income tax at 21% applies on top, which pushes the combined effective burden on a profitable California C corp to roughly 28% to 30% once the state deduction is factored in.
How the 8.84% Rate Works
The 8.84% rate is flat. It doesn’t step up with income the way individual rates do, so a corporation with $50,000 in net income and one with $50 million pay at the same percentage. California calls it a franchise tax because it’s imposed for the privilege of doing business in the state, but the math is a straightforward income tax.
A corporation owes whichever is greater: 8.84% of California net income or the $800 minimum. A corporation with $5,000 in net income calculates $442 under the percentage, but still pays $800. At $100,000 in net income, the tax is $8,840, which exceeds the floor.1California Taxes. C Corporations Tax Information
Banks and Financial Corporations Pay 10.84%
Financial corporations face a two-percentage-point premium at 10.84%. In exchange, they’re generally exempt from certain other state and local taxes that non-financial businesses pay.2Franchise Tax Board. Business Tax Rates
The $800 Minimum Franchise Tax
The $800 minimum applies to every C corporation incorporated, registered, or doing business in California, regardless of income. It’s owed in loss years, dormant years, and startup years with no revenue. For calendar-year corporations, it’s due by April 15.3California Franchise Tax Board. C Corporations
First-Year Exemption
Corporations incorporated or qualified to do business in California on or after January 1, 2020, are exempt from the $800 minimum in their first taxable year. The exemption only covers the minimum. If the corporation earns income that first year, 8.84% still applies to it.4Franchise Tax Board. Corporations
Short Tax Years
A corporation with a tax year of 15 days or fewer that conducted no California business during that period is exempt from the $800. Outside that narrow window, the full amount applies no matter how short the year.4Franchise Tax Board. Corporations
Closing the Corporation
The $800 keeps accruing every year until the corporation properly closes out with California. Simply stopping operations isn’t enough. The corporation must file a final return by the extended due date, mark it “FINAL,” halt all California business activity, and file dissolution or surrender paperwork with the Secretary of State within 12 months of the final return. Miss a step and the minimum tax keeps coming, along with penalties.5California Franchise Tax Board. Closing a California Business Entity
The Federal Layer
The 8.84% figure is only the state piece. C corporations also owe federal corporate income tax at 21%. State taxes are deductible on the federal return, so the combined rate isn’t a straight sum, but the total lands near 28% to 30% for profitable California corporations. Reading the state rate in isolation is one of the more common planning mistakes.
What “Net Income” Means in California
California starts with federal taxable income and then adjusts where its rules diverge from the Internal Revenue Code. For multi-state corporations, an apportionment step decides how much of that income California can tax.
Where California Departs From Federal Rules
- Bonus depreciation under IRC Section 168(k) is not allowed. Corporations that took accelerated depreciation federally must add back the difference and use California’s own schedule.
- The federal Section 163(j) limit on business interest deductions doesn’t apply. California uses its own rules.
- Net operating losses are suspended for taxable years 2024 through 2026 for corporations with California income of $1 million or more. Corporations below that threshold can still use NOLs, and all corporations can continue to compute and carry losses forward. The carryover period extends by one year for each suspension year, and disaster losses are unaffected.6California Franchise Tax Board. Net Operating Loss
These adjustments can move California taxable income noticeably away from the federal figure before apportionment even enters the picture.
Apportionment for Multi-State Corporations
A corporation doing business inside and outside California pays 8.84% only on the California share. Most industries use a single-sales factor: the ratio of California sales to total sales everywhere. Property and payroll located in California don’t enter the calculation.7State of California Franchise Tax Board. Apportionment and Allocation
This tends to favor corporations with California employees and facilities that sell mostly to out-of-state customers. It cuts the other way for an out-of-state corporation with few California workers but heavy California sales. Corporations that derive more than 50% of gross receipts from certain qualified activities, primarily agricultural and extractive industries, must use the older three-factor formula weighing property, payroll, and sales equally.
Deadlines and Estimated Payments
C corporations file Form 100 with the Franchise Tax Board. The return is due the 15th day of the fourth month after the tax year closes, so April 15 for calendar-year corporations. California grants an automatic seven-month extension to file, pushing the calendar-year deadline to November 15 with no application required. The extension covers filing only. Payment is still due on the original date.8California Franchise Tax Board. Due Dates: Businesses9California Franchise Tax Board. Extension to File
When expected tax exceeds the $800 minimum, the corporation owes estimated payments during the year, on the 15th day of the 4th, 6th, 9th, and 12th months:
- 4th month: 30% of estimated tax
- 6th month: 40% of estimated tax
- 9th month: nothing due
- 12th month: 30% of estimated tax
If total estimated tax doesn’t exceed the $800 minimum, the whole $800 is due as a single payment by the 15th day of the fourth month.10State of California Franchise Tax Board. 2025 Instructions for Form 100-ES Corporation Estimated Tax
Penalties for Missing a Deadline
Late filing costs 5% of unpaid tax per month or partial month, capped at 25%. If the FTB sends a formal demand to file and the corporation still doesn’t file, the penalty jumps to 25% of total tax due regardless of any payments already made. Interest on unpaid tax adjusts semiannually; the corporation underpayment rate for the period from July 1, 2025, through June 30, 2026, is 7%. Underpaid estimated installments carry a separate penalty at the same 7% rate for that period.11State of California Franchise Tax Board. Interest and Estimate Penalty Rates
Late-filing penalties and interest run together, so a corporation that files late and pays late can rack up 25% in penalties plus months of interest. Filing on time and paying what you can, even if it isn’t the full balance, limits the damage.12State of California Franchise Tax Board. Common Penalties and Fees
Credits That Reduce the Bill
Credits offset the 8.84% tax but never the $800 minimum. Widely used ones include:
- Research credit at 15% of qualified research expenses above a base amount, with an alternative simplified calculation available at a lower percentage.13State of California Franchise Tax Board. 2025 Instructions for Form FTB 3523 Research Credit
- California Competes credit, a negotiated credit for businesses committing to jobs or capital investment in the state, with over $180 million allocated annually across application windows open to any size or industry.14California Governor’s Office of Business and Economic Development (GO-Biz). California Competes
- Homeless Hiring credit through the end of 2026, worth up to $10,000 per qualifying employee and $30,000 per employer annually, scaling with hours worked.15Franchise Tax Board. Homeless Hiring Tax Credit
Other credits target low-income housing investment and hiring in specific enterprise zones. The FTB publishes a full current list with each year’s Form 100 instructions.