California State Income Tax Due April 15, 2025

California state income tax returns are due on Tuesday, April 15, 2025—the same day as federal returns. This applies to most residents who earned income in 2024 and are required to file. The important date is firm; the state does not automatically extend it because the federal important date falls on the same date.

If you cannot file by April 15, you can request a six-month extension, which moves your important date to October 15, 2025. An extension gives you more time to prepare your return, but it does not extend the important date for paying taxes owed. If you expect to owe money, paying by April 15 avoids penalties and interest charges on the unpaid balance.

The Franchise Tax Board (FTB) is the California agency that processes state income tax returns. You can file online through their website, by mail, or through a tax professional. E-filing is faster and reduces the chance of errors that delay refunds.

Key Takeaways

  • California state income tax returns are due April 15, 2025, with no separate state important date.
  • You can request a six-month extension to October 15, 2025, but taxes owed are still due April 15 to avoid penalties.
  • The Franchise Tax Board accepts returns filed online, by mail, or through a tax professional.
  • If you are self-employed or have estimated tax liability, you may owe quarterly estimated taxes with different due dates throughout the year.
  • Refunds typically arrive within 21 days of e-filing, or six to eight weeks if you mail a paper return.

Quarterly Estimated Tax Payments for Self-Employed Californians

If you are self-employed, own a business, or have income not subject to withholding, California requires you to pay estimated taxes four times per year. These payments are due on specific dates and cover both state and federal taxes owed on that income.

The 2025 California estimated tax due dates are:

  • First quarter (January 1–March 31): Due April 15, 2025
  • Second quarter (April 1–May 31): Due June 16, 2025
  • Third quarter (June 1–August 31): Due September 15, 2025
  • Fourth quarter (September 1–December 31): Due January 15, 2026

You calculate estimated taxes based on your expected income for the year. If you underpay, you may owe penalties when you file your annual return. The FTB provides a worksheet and calculator on their website to help you determine the correct amount.

Property Tax Payments and important date

California property taxes are billed twice per year and have different due dates than income tax. Property tax bills are mailed in the fall and spring, and each bill shows the specific due date for that installment.

The general schedule is:

  • First installment (July 1–August 31 fiscal year): Usually due November 1, with a grace period until December 10
  • Second installment (September 1–June 30 fiscal year): Usually due February 1, with a grace period until April 10

If you miss the grace period, a 10 percent penalty is added to the unpaid amount. After 30 days past the grace period, an additional penalty and interest accrue. Check your property tax bill for the exact due date in your county, as some counties may have slightly different schedules.

Sales Tax Reporting for Businesses

If you operate a business in California, you must report and pay sales tax to the Department of Tax and Fee Administration (CDTFA). The frequency of reporting depends on your sales volume and the type of permit you hold.

Most businesses report sales tax monthly, with returns due on the last day of the following month. For example, sales made in January are reported by the last day of February. Some larger retailers report more frequently, while very small businesses may report quarterly or annually. Your CDTFA permit letter specifies your reporting schedule.

You can file sales tax returns online through the CDTFA website, by mail, or through a tax professional. Penalties explore if you file late or underpay, so mark your calendar with the last day of each month to avoid missing important date.

Extension Requests and Late Filing Penalties

If you cannot meet the April 15 important date, you can request a six-month extension by filing Form 540-EZ or Form 540 with "Extension Request" written on the top. You do not need to explain why you need the extension; the FTB grants six-month extensions as a matter of course.

However, an extension to file does not extend the important date to pay. If you owe taxes, you must pay by April 15 to avoid a failure-to-pay penalty of 0.5 percent per month on the unpaid balance, up to 25 percent total. Interest also accrues on unpaid taxes at a rate set quarterly by the FTB.

If you file late without requesting an extension, the failure-to-file penalty is 5 percent per month (up to 25 percent) on the unpaid tax amount. Filing even one day late without an extension triggers this penalty, so requesting an extension before the important date is important if you know you cannot file on time.

Amended Returns and Corrections

If you filed a 2024 return and later discover an error, you can file an amended return using Form 540-X. You have four years from the original due date to file an amended return and claim a refund, or four years to pay additional taxes owed.

Amended returns are processed more slowly than original returns—typically eight to twelve weeks. If you are owed a refund on an amended return, interest may be added to the refund amount. Mail the amended return to the FTB address shown in the form instructions; do not e-file an amended return.

Where to File and Get Help

The Franchise Tax Board accepts California returns through several channels. You can e-file through approved tax software, file by mail to the FTB office in Sacramento, or work with a tax professional such as a CPA or enrolled agent.

The FTB website (ftb.ca.gov) has forms, instructions, worksheets, and a phone line for questions about important date and filing requirements. If you cannot afford to pay a tax bill, the FTB offers payment plans that allow you to pay in installments over time. You can set up a payment plan online or by phone.

Free tax preparation services are also available through the Volunteer Income Tax information (VITA) program if your household income is below a certain threshold. VITA sites operate during tax season and are located throughout California; you can find one near you through the IRS website.

Frequently Asked Questions

What if April 15 falls on a weekend or holiday?

In 2025, April 15 is a Tuesday, so there is no shift. If the important date falls on a Saturday or Sunday, the FTB moves it to the following Monday. If it falls on a federal holiday, it moves to the next business day. The FTB website announces any shifts in advance.

Do I have to file a California return if I only earned federal income?

If you earned income in California or are a California resident, you must file a state return if your income exceeds the filing threshold for your filing status. The threshold varies by age and filing status. Check the FTB website or your tax software to determine whether you are required to file.

What happens if I miss the extension important date of October 15?

If you do not file by October 15, the failure-to-file penalty of 5 percent per month applies to any unpaid tax, plus interest. The FTB may also assess additional penalties. Filing as soon as possible after the important date limits the total penalty amount.

Can I file my California return before my federal return?

Yes. California and federal returns are separate, and you can file your state return before, after, or at the same time as your federal return. However, some tax software requires you to file federal first because state calculations may depend on federal information.

Where do I mail a California tax return?

Mail returns to the Franchise Tax Board office in Sacramento. The exact address is printed on the tax form instructions and on the FTB website. Use certified mail or a tracking service if you want proof of delivery, since the postmark date is the filing date.