Business Tax Deadlines

State filing information

California

Business tax filing in California: state returns, sales tax, other business taxes, and the federal dates that apply everywhere.

checked 2026-09-01Verified against California Franchise Tax Board (income/franchise taxes); California Department of Tax and Fee Administration (sales and use tax). 13 sources.

Corporate income tax return

April 15
Corporation franchise/income tax return (Form 100) due the 15th day of the 4th month after the close of the tax year; $800 minimum franchise tax

Partnership / S corporation returns

March 15
Partnerships March 15; Same for S corporations

Sales tax return

Last day of the following month
sales and use tax · CDTFA assigns quarterly-prepay, quarterly, monthly, fiscal-yearly or yearly filing based on reported sales tax or anticipated taxable sales at...

Other business taxes

2 taxes
LLC annual tax ($800) and LLC fee; Minimum franchise tax ($800) for corporations and S corporations

California Franchise Tax Board · also California Department of Tax and Fee Administration (sales and use tax)

Other business taxes

TaxWho owes itDue
LLC annual tax ($800) and LLC feeEvery LLC doing business or registered in California (annual tax due even if not conducting business until the LLC is cancelled)Annual $800 tax: 15th day of the 4th month of the taxable year...
Minimum franchise tax ($800) for corporations and S corporationsCorporations and S corporations doing business or registered in California (first-year exemption rules not verified here)Paid with estimated tax

Rules in full

Corporate income tax

Corporation franchise/income tax return (Form 100) due the 15th day of the 4th month after the close of the tax year; $800 minimum franchise tax.

Extension. Automatic 7-month paperless extension to file (15th day of the 11th month; November 15 for calendar year). Not an extension to pay (use FTB 3539)

Partnerships and S corporations

S corporations are taxed at entity level at 1.5% of net income with an $800 minimum franchise tax. Separately, the elective Pass-Through Entity (PTE) tax is available for taxable years beginning on/after 1/1/2021 and before 1/1/2031 (extended through 2030); election is made on a timely filed original return (FTB 3804) and, for 2022-2030, an initial payment is due June 15 of the election year (for 2026-2030 a missed June 15 payment reduces the credit by 12.5% of the shortfall rather than voiding the election). LLCs owe the $800 annual tax by the 15th day of the 4th month of the tax year and must estimate the LLC fee by the 15th day of the 6th month.

Sales and use tax

Due date. Returns are due the last day of the month following the reporting period (e.g., quarterly returns April 30, July 31, October 31, January 31; monthly returns last day of the following month). Yearly filers: January 31.

Filing frequency. CDTFA assigns quarterly-prepay, quarterly, monthly, fiscal-yearly or yearly filing based on reported sales tax or anticipated taxable sales at registration.

Prepayments. Taxpayers whose estimated measure of tax liability averages $17,000 or more per month are placed on a quarterly prepayment basis (R&TC 6471): prepayments for the first two months of each quarter are due by the 24th of the following month (e.g., Feb 24 and Mar 24 for Q1), then the quarterly return by the last day of the month after quarter end.

Notes

Change effective 2026: the PTE elective tax was extended through taxable years beginning before 1/1/2031 with a modified June 15 prepayment rule. Statement of Information filings are with the Secretary of State and were not chased.

What we could not confirm. CDTFA does not publish dollar thresholds for monthly/quarterly/yearly assignment on the pages fetched (only the $17,000/month prepayment trigger), so thresholds are null. First-year minimum-tax exemption rules were not reviewed.

Federal dates that apply in California

  1. SEP15Tue
    Individuals & Sole Proprietors
    Q3 2026 estimated tax payment (Form 1040-ES)
  2. SEP15Tue
    Partnerships
    Form 1065 extended return (Form 7004), tax year 2025
  3. SEP15Tue
    S-Corporations
    Form 1120-S extended return (Form 7004), tax year 2025
  4. SEP15Tue
    C-Corporations
    Q3 2026 corporate estimated tax (Form 1120-W)
  5. OCT15Thu
    Individuals & Sole Proprietors
    Form 1040 extended return (Form 4868), tax year 2025
  6. OCT15Thu
    C-Corporations
    Form 1120 extended return (Form 7004), tax year 2025

All 2026 federal deadlines

Sources

  1. https://www.ftb.ca.gov/file/when-to-file/due-dates-business.html official
  2. https://www.ftb.ca.gov/ official
  3. https://www.cdtfa.ca.gov/ official
  4. https://www.ftb.ca.gov/file/business/types/corporations/index.html official
  5. https://www.ftb.ca.gov/file/business/types/corporations/s-corporations.html official
  6. https://www.ftb.ca.gov/file/business/credits/pass-through-entity-elective-tax/index.html official
  7. https://www.cdtfa.ca.gov/taxes-and-fees/sales-use-tax-returns-filing-dates.htm official
  8. https://www.cdtfa.ca.gov/services/make-a-prepayment.htm official
  9. https://www.cdtfa.ca.gov/formspubs/cdtfa367sut.pdf official
  10. https://www.ftb.ca.gov/file/business/types/limited-liability-company/index.html official
  11. https://www.instead.com/state-tax-deadlines/2025-california-state-tax-deadlines
  12. https://www.taxjar.com/sales-tax/california
  13. https://www.avalara.com/taxrates/en/state-rates/california/california-sales-tax-guide.html

Checked 2026-09-01; researcher confidence 0.90. Corrections with a link to the state's own page: contact@businesstaxdeadlines.com.