California’s estimated tax rules can trip up even the most diligent entrepreneurs. Many freelancers and small‑business owners assume the state follows the Internal Revenue Service’s evenly split quarterly schedule. It doesn’t. The Franchise Tax Board (FTB) front‑loads your tax liability—30% is due in April, 40% in June, nothing in September and the remaining 30% in January. Miss a deadline and the FTB immediately assesses penalties and interest from ftb.ca.gov. To keep you penalty‑free, this guide breaks down the 2025 deadlines, explains how to calculate your payments, and shares practical tips for staying compliant.

Quick Answer: 2025 California estimated tax deadlines

California’s four payment periods don’t follow the federal 25/25/25/25 split. Instead, you must pay 30 percent of your annual tax by April 15, 40 percent by June 16, nothing on September 15 and the final 30 percent by January 15, 2026 from ftb.ca.gov. Here’s a handy comparison of the state and federal schedules:

*Percentages refer to the required portion of your annual California tax. If you file your return by January 31, 2026 and pay the balance due, you can skip the fourth installment from ftb.ca.gov.

Why California’s rules differ from the IRS

Unlike the IRS, which divides payments evenly throughout the year, California wants more of its money up front. Under state law, your first and second installments must cover 70% of the year’s tax (30% and 40%) from ftb.ca.gov. The state doesn’t require a September payment at all, which often causes confusion for taxpayers accustomed to the federal schedule. If you follow the IRS’s 25/25/25/25 rhythm for state payments, you’ll underpay the first two quarters and be hit with penalties from ftb.ca.gov.

Penalties for missing or underpaying

The FTB doesn’t send friendly reminders. If you miss a payment date or pay less than required, a penalty accrues immediately on the underpaid amount. Penalties include:

• 5% of the unpaid tax, plus 0.5% per month (or part of a month) the tax remains unpaid—up to 40 months from taxaudit.com.

• A 1% penalty if you are subject to mandatory e‑payment but send a paper check from ftb.ca.gov.

• Additional interest (currently around 7%) compounded on underpayments from kdainc.com.

Because penalties compound quickly, paying early and setting up reminders is essential. If you overpay a quarter, the excess is automatically credited to your next installment from kdainc.com.

Who must pay California estimated taxes?

If your employer withholds all of your state income tax (you’re a regular W‑2 employee), you may not need to make estimated payments. However, you must pay estimates if your withholding and credits will be less than either:

• 90% of the tax shown on your 2025 return, or

• 100% of your 2024 tax liability from ftb.ca.gov.

For high‑income taxpayers—those with 2024 adjusted gross income above $150,000 (or $75,000 if married filing separately)—the safe‑harbor rises to 110% of last year’s tax from ftb.ca.gov. If your 2025 AGI is $1 million or more (or $500,000 if married filing separately), you must base your payments on 90% of this year’s tax from ftb.ca.gov.

Who usually owes estimated taxes?

• Freelancers and independent contractors (1099‑NEC or 1099‑MISC income)

• LLC members or S‑Corp shareholders receiving distributions

• Real‑estate investors with rental or capital‑gains income

• High‑income taxpayers whose W‑2 withholding is insufficient

• Side‑gig earners (ride‑share drivers, online sellers, consultants)

If you expect to owe more than $500 ($250 if married filing separately) after subtracting withholdings and credits, the FTB expects you to make quarterly payments from ftb.ca.gov.

How to calculate your estimated payments

Follow these steps to estimate what you owe for 2025:

1. Determine last year’s tax – Look up your 2024 California tax liability on Form 540 or 540NR. If your income was over $150,000 ($75,000 when filing separately), multiply this number by 110% from ftb.ca.gov; otherwise use 100%. If your 2025 AGI is likely to exceed $1 million, skip this step and project your current year’s liability from ftb.ca.gov.

2. Project current‑year income – Estimate 2025 earnings from self‑employment, investments, and other sources. Use the California Estimated Tax Worksheet or consult a tax professional.

3. Choose your safe‑harbor – Your required annual payment is the lesser of (a) 90% of your projected 2025 tax or (b) the prior‑year safe‑harbor from step 1 from ftb.ca.gov.

4. Apply the CA schedule – Multiply your required annual payment by 30%, 40%, 0%, and 30% to get your quarterly amounts from ftb.ca.gov.

5. Set calendar reminders – Plan to pay by the CA due dates (April 15, June 16, September 15, January 15) from ftb.ca.gov.

Example calculation

Suppose your 2024 California tax liability was $8,000 and your 2024 AGI was $155,000 (above the $150K threshold). To meet the safe‑harbor, multiply $8,000 by 110% = $8,800. Your quarterly payments would be:

If your income increases during the year, adjust future payments upward to avoid underpayment penalties. Overpayments will carry forward to the next installment from kdainc.com.

Avoid the September trap

Many taxpayers mistakenly send a payment in September because that’s when the IRS expects its third installment. The FTB does not require a September payment from ftb.ca.gov. Paying in September unnecessarily ties up your cash until you file your annual return and doesn’t reduce penalty risk. Instead, ensure that you’ve met your 70% requirement by June and prepare for the final 30% due in January.

Book Your 2025 Estimated Tax Penalty Review

If you’re unsure about your payment schedule, facing an FTB penalty notice, or want to streamline your compliance before deadlines hit, book a custom tax session with our team. You’ll walk away with a calendar, a penalty risk review, and a plan that saves you hundreds (if not thousands) this year. Click here to grab your 2025 penalty-proof tax calendar consultation now.

“The IRS isn’t hiding these penalty traps—you just have to know where California’s FTB loads the landmines.”

Multi-Channel Takeaways

• Missing just one California estimated tax payment can trigger hundreds in penalties—know your state’s unique schedule for 2025.
• The FTB’s split schedule (30/40/0/30) is not the same as the IRS—paying 25% quarterly can cost you big time.
• Book your 2025 penalty-proof tax calendar session now—keep your cash and your peace of mind.