The California C corp tax rate is a flat 8.84% of net income attributable to the state, with an $800 minimum franchise tax that every C corporation owes each year even if it earned nothing. A corporation pays whichever is greater. That state tax sits on top of the 21% federal corporate income tax, so a profitable California C corp typically faces a combined rate near 28% to 30% after accounting for the federal deduction for state taxes paid.
How the 8.84% Rate and $800 Minimum Fit Together
The 8.84% rate is flat. It applies the same way to a corporation with $50,000 of California net income as to one with $50 million. The tax is formally called a franchise tax because it’s imposed for the privilege of doing business in the state, but it functions as an income tax.
Every year, a corporation calculates 8.84% of its California net income and compares that figure to $800. It pays the larger number. A corporation with $5,000 of net income would owe $442 under the percentage calculation, so it pays the $800 minimum instead. A corporation with $100,000 of net income owes $8,840, which exceeds the floor, so the minimum doesn’t come into play.1California Taxes. C Corporations Tax Information
Banks and Financial Corporations Pay 10.84%
Banks and financial corporations face a higher rate of 10.84% on net income. The two-point premium reflects a trade-off: these corporations pay more income tax but are generally exempt from certain other state and local taxes that apply to non-financial businesses.2Franchise Tax Board. Business Tax Rates
The $800 Minimum in Detail
Any C corporation incorporated, registered, or doing business in California owes the $800 minimum franchise tax annually. It applies in loss years, in zero-revenue years, and in years the corporation sat dormant. For calendar-year corporations, the minimum is due by April 15 of the tax year.3California Franchise Tax Board. C Corporations
First-Year Exemption
Corporations incorporated or qualified to do business in California on or after January 1, 2020, don’t owe the $800 minimum in their first taxable year. The exemption covers only the minimum. If the corporation actually earns income during year one, it still owes 8.84% on that income.4Franchise Tax Board. Corporations
Very Short Tax Years
A corporation with a tax year of 15 days or fewer that conducted no business in California during that period is exempt from the $800. Outside that narrow situation, the full $800 is due regardless of how short the year was.4Franchise Tax Board. Corporations
Stopping the Clock When You Close Down
The $800 keeps accruing every year until you properly close out your California obligations. Simply stopping operations isn’t enough. To avoid the minimum for the following year, a corporation must file its final tax return by the extended due date, mark it “FINAL,” halt all California business activity after that final year, and file dissolution or surrender paperwork with the Secretary of State within 12 months of the final return. Missing any of these steps can leave the corporation on the hook for additional years of the $800, plus penalties.5California Franchise Tax Board. Closing a California Business Entity
Federal Tax Is Separate
The 8.84% is only the California piece. C corporations also owe federal corporate income tax at a flat 21%. Because state taxes are deductible on the federal return, the combined effective rate isn’t a straight sum, but it typically lands near 28% to 30% for profitable California corporations. The state rate looks modest on its own, and that’s part of why the overall burden surprises people: the federal layer roughly triples it.
What California Actually Taxes
California starts with federal taxable income and then adjusts for places where state law differs from the Internal Revenue Code. For multi-state corporations, apportionment then narrows the income down to what California can tax.
Where California Diverges From Federal Rules
- California does not conform to federal bonus depreciation under IRC Section 168(k). Corporations that take accelerated depreciation federally must add back the difference and apply California’s depreciation schedule.
- California does not follow the federal Section 163(j) limitation on business interest deductions and applies its own rules.
- For taxable years 2024 through 2026, California has suspended the net operating loss deduction for corporations with California income of $1 million or more. Smaller corporations can still use their NOLs, and all corporations can continue to compute and carry losses over during the suspension. The carryover period is extended by one year for each year of suspension, and disaster losses are not affected.6California Franchise Tax Board. Net Operating Loss
Because of these adjustments, California taxable income can look meaningfully different from the federal figure even before apportionment.
Apportionment for Multi-State Corporations
A corporation doing business both inside and outside California pays 8.84% only on the California share of income. Most corporations use a single-sales factor formula: 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 large California workforces that sell to customers elsewhere. An out-of-state corporation selling heavily into California will see more of its income pulled into the state tax base.
The single-sales factor is mandatory for most industries. Corporations that derive more than 50% of their gross receipts from certain qualified activities, primarily agricultural and extractive industries, must use the older three-factor formula weighting property, payroll, and sales equally.7State of California Franchise Tax Board. Apportionment and Allocation
Filing Deadlines and Estimated Payments
C corporations file Form 100 with the Franchise Tax Board. The return is due by the 15th day of the fourth month after the close of the tax year, so April 15 for calendar-year filers.8California Franchise Tax Board. Due Dates: Businesses
California grants an automatic seven-month extension to file. No request is needed. For calendar-year corporations, the extended deadline is November 15. The extension covers filing only. Payment is still due by April 15.9California Franchise Tax Board. Extension to File
When expected tax exceeds the $800 minimum, estimated payments are required during the year. California’s installment pattern is unusual, so watch it closely. Payments are due on the 15th day of the 4th, 6th, 9th, and 12th months of the tax year, split as:
- First installment (4th month): 30% of estimated tax
- Second installment (6th month): 40% of estimated tax
- Third installment (9th month): no payment due
- Fourth installment (12th month): 30% of estimated tax
If total estimated tax doesn’t exceed the $800 minimum, the full minimum 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 Deadlines
Late filings and late payments get expensive quickly, and the penalties stack with interest.
- Late filing penalty: 5% of the unpaid tax for each month or partial month the return is overdue, capped at 25%.
- Demand penalty: if the FTB sends a formal demand letter and the corporation still doesn’t file, the penalty becomes 25% of the total tax due, regardless of any payments already made.
- Underpayment interest: adjusted semiannually. For July 1, 2025 through June 30, 2026, the corporation underpayment rate is 7%.
- Estimated tax penalty: a separate charge for underpaid quarterly installments, also 7% for the same period.11State of California Franchise Tax Board. Interest and Estimate Penalty Rates
Late filing penalties and interest run concurrently, so a corporation that files late and pays late can face a 25% penalty plus months of accruing interest. Filing on time and paying what you can, even if it isn’t the full amount, keeps the damage much smaller.12State of California Franchise Tax Board. Common Penalties and Fees
Credits That Can Lower the Bill
Several California credits offset tax calculated at 8.84%. None of them reduce the $800 minimum. Among the more widely used:
- Research credit: 15% of qualified research expenses above a base amount. An alternative simplified calculation at a lower percentage is also available.13State of California Franchise Tax Board. 2025 Instructions for Form FTB 3523 Research Credit
- California Competes credit: a negotiated, competitive credit for businesses committing to job creation or capital investment in the state. Open to any size or industry during designated application windows, with over $180 million allocated annually.14California Governor’s Office of Business and Economic Development (GO-Biz). California Competes
- Homeless Hiring credit: through the end of 2026, up to $10,000 per qualifying employee hired from the homeless population, capped at $30,000 per employer per year. The amount scales with hours worked.15Franchise Tax Board. Homeless Hiring Tax Credit
Other credits apply to specific activities such as low-income housing investment and hiring within designated enterprise zones. The FTB publishes the current list with each year’s Form 100 instructions.