California Estimated Tax Payments: Due Dates, Safe Harbors & Penalties

If you expect to owe at least $500 in California income tax for 2026 after withholding and credits ($250 if married or in an RDP filing separately), you need to make California estimated tax payments to the Franchise Tax Board. The payments go out in four installments on an unusual 30/40/0/30 schedule, and the FTB charges 7% annual interest on any shortfall.¹²

Who Has to Pay

The $500 threshold catches self-employed workers, freelancers, landlords, investors with significant capital gains or dividends, and anyone else receiving substantial income without California tax withheld. New residents and nonresidents who had no California tax liability in 2025 don’t owe estimated payments for 2026 at all.³

The dollar threshold isn’t the whole test. You also need to look at whether your withholding and credits will clear one of the safe harbor minimums below. If they will, you can stop worrying about estimated payments regardless of what you ultimately owe at filing.

Due Dates and the 30/40/0/30 Split

California front-loads estimated payments and skips the third quarter entirely. The four 2026 installments are:

April 15, 2026 — 30% of the required annual payment
June 15, 2026 — 40% of the required annual payment
September 15, 2026 — 0% (no payment due)
January 15, 2027 — 30% of the required annual payment

If a due date falls on a weekend or legal holiday, the deadline moves to the next business day.⁴

Seventy percent of the annual obligation is due by mid-June. The September installment of 0% is not a typo; California simply doesn’t require a third-quarter payment. Nothing is owed between June and January, and then the last 30% lands in January.¹

Safe Harbors That Keep You Penalty-Free

You avoid an underpayment penalty if your combined withholding and estimated payments equal the smaller of two numbers: 90% of your 2026 California tax, or 100% of the tax shown on your 2025 California return (including any AMT). Meet either benchmark and the FTB won’t penalize you, even if you still owe a balance at filing.¹

Higher-income taxpayers face stricter rules. If your 2025 California AGI was more than $150,000 ($75,000 if married or RDP filing separately), the prior-year safe harbor rises from 100% to 110%. You pay the lesser of 90% of 2026 tax or 110% of 2025 tax.³

Once 2026 California AGI reaches $1,000,000 ($500,000 if married or RDP filing separately), the prior-year safe harbor vanishes. Payments must be based on 90% of current-year tax.¹ This is the rule that catches people with one unusually big year: earning $1.2 million in 2026 after $200,000 in 2025 means paying based on last year’s tax guarantees a penalty.

Calculating What You Owe

The California Estimated Tax Worksheet in the Form 540-ES instructions walks through the math.³ Project your 2026 AGI, subtract deductions and credits to estimate total tax, compare the two safe harbor figures, and divide the smaller one across the 30/40/0/30 schedule.

The 2026 standard deduction is $5,706 for single or married/RDP filing separately, and $11,412 for married/RDP filing jointly, head of household, or qualifying surviving spouse/RDP.¹ Itemizers use their itemized total.

The Behavioral Health Services Tax

Taxable income above $1,000,000 is subject to an additional 1% Behavioral Health Services Tax, and the 2026 Form 540-ES instructions include a dedicated worksheet for it.¹ The 1% applies only to the portion above $1,000,000, so a taxpayer with $1.5 million in taxable income owes an extra 1% on $500,000. It’s easy to miss when using a prior-year return as a starting point and income crossed the threshold for the first time.

Adjusting During the Year

Income rarely tracks the plan exactly. If a large freelance project lands, rental income drops, or you sell investments, recalculate before the next installment. The FTB encourages recalculating each period for accuracy.³ There’s no separate form; just send a different amount for the next installment.

How to Pay

FTB Web Pay pulls directly from your bank account and is the fastest option. Through MyFTB you can schedule all four installments at the start of the year.⁵ Sole proprietors use Web Pay personal, not the business version.

Credit card payments go through ACI Payments, the FTB’s third-party processor, with a 2.3% service fee on the full payment.⁶ Mailed payments use Form 540-ES as the voucher, with the check or money order made payable to “Franchise Tax Board” and your SSN or ITIN and the tax year written on the payment.

After submitting, verify the payment posted through your MyFTB account.⁷ This matters most for mailed payments, which can take a couple of weeks to process.

Mandatory Electronic Payment Rules

Once you make any estimated or extension payment over $20,000, or file a return showing total tax liability over $80,000, every future payment must be electronic regardless of amount. The trigger is permanent. The payment that first crosses the threshold doesn’t itself have to be electronic, but each one after it does. The noncompliance penalty is 1% of the payment amount.¹

Using Paycheck Withholding Instead

If you also have wage income, you can often skip estimated payments by withholding more from your paycheck. Figure the annual estimated tax, divide by remaining pay periods, and request that amount as additional withholding.

For California, file a new Form DE 4 with your employer and enter the extra per-period amount on line 2.⁸ For federal, use Form W-4, Step 4(c).⁹

Withholding carries a real advantage over estimated payments: it’s treated as paid evenly across the year no matter when it was actually deducted. Realize in October that you’ve underpaid, and raising withholding for the remaining paychecks can cover earlier quarters retroactively. A September estimated payment only counts toward the September installment period.

Underpayment Penalties and the Exceptions

Missing a deadline or paying too little triggers an underpayment penalty, even if your return ends up showing a refund. The penalty works like interest, charged at 7% annually on the shortfall for the time it stayed unpaid.² The FTB usually calculates it after you file and bills you; you won’t necessarily know the amount in advance.¹⁰

To calculate it yourself or claim an exception, use Form FTB 5805. Most people let the FTB do the math, but the form matters if you qualify for the annualized income installment method.

Annualized Income Installment Method

This method is for people whose income arrives unevenly. If most of your income came in the fourth quarter, you shouldn’t be penalized for not making large payments in April and June. The annualized method recalculates each period’s required payment based on income actually received through that point rather than assuming even earnings all year.¹⁰ Part III of Form 5805 handles the calculation across four cumulative periods. If you use this method for any installment, you must use it for all four.

Filing Early to Skip Penalties Entirely

You can wipe out the underpayment penalty for the whole year by filing your California return and paying everything due by March 1 of the following year. For 2026, that means filing and paying in full by March 1, 2027.¹⁰ This eliminates the penalty entirely, not just for the fourth installment. The tradeoff is assembling tax documents about six weeks earlier than the normal April deadline.

How California Differs From Federal Estimated Taxes

If you also owe federal estimated taxes, you’re running two parallel systems with different rules. The due dates match — April 15, June 15, September 15, and January 15 — but almost everything else differs:

The IRS requires estimated payments at $1,000 of expected tax; California requires them at $500 ($250 if married filing separately). You can owe California estimated tax while staying under the federal threshold.¹¹
Federal installments are 25% each quarter. California uses 30/40/0/30.
Both systems raise the prior-year safe harbor to 110% at $150,000 AGI, but California removes the prior-year safe harbor altogether at $1,000,000 AGI. The federal 110% option continues at every income level.³

Send the payments separately: federal to the IRS, California to the FTB.

For most taxpayers with predictable income, the easiest path through all of this is to pay 100% of last year’s California tax (or 110% if your 2025 AGI topped $150,000) spread across the 30/40/0/30 schedule and let the safe harbor do the work. For anyone whose 2026 AGI will hit $1,000,000, prior-year math doesn’t help, and the only reliable approach is working from current-year projections and recalculating before each installment.

1
Franchise Tax Board. 2026 Instructions for Form 540-ES Estimated Tax for Individuals
2
Franchise Tax Board. Interest and Estimate Penalty Rates
3
Franchise Tax Board. Estimated Tax Payments
4
Franchise Tax Board. When to File – Personal Income Tax Due Dates
5
Franchise Tax Board. Pay by Bank Account (Web Pay)
6
Franchise Tax Board. Pay by Credit Card
7
Franchise Tax Board. MyFTB Account
8
Employment Development Department. Employee’s Withholding Allowance Certificate (DE 4)
9
Internal Revenue Service. Form W-4, Employee’s Withholding Certificate
10
Franchise Tax Board. 2024 Instructions for Form FTB 5805
11
Internal Revenue Service. Estimated Tax