California Estimated Tax Payments: Due Dates, Safe Harbor, and Penalties

California estimated tax payments are quarterly prepayments to the Franchise Tax Board (FTB) that you owe if you expect at least $500 in California income tax beyond what withholding and credits cover ($250 if you’re married or in a registered domestic partnership filing separately).¹ They follow a front-loaded schedule that doesn’t match the federal 25%-per-quarter pattern, and missing an installment generates a penalty calculated like interest on the shortfall.

Who Owes Estimated Payments

Two conditions have to be true before the requirement kicks in. You expect to owe $500 or more in California tax after subtracting withholding and credits ($250 if married or RDP filing separately), and your withholding and credits are projected to fall below one of the safe harbor thresholds described below.¹

The income types that typically push people into this requirement are self-employment and independent contractor earnings, rental property income, capital gains from selling investments or real estate, alimony received, and interest or dividend income. Wage withholding counts against your annual obligation, so a W-2 employee with a side consulting practice may still be fine if the withholding on the day job covers the extra tax.

How Much You Need to Pay

California uses safe harbor rules to set the minimum. Pay enough to clear a safe harbor and no underpayment penalty applies, even if you still owe money when you file. The rule that applies to you depends on your income.

General Safe Harbor

For most taxpayers, your combined withholding plus estimated payments must equal at least the smaller of these two figures: 90% of the current year’s tax, or 100% of the prior year’s tax (including any alternative minimum tax).²

Higher-Income Taxpayers

If your prior-year California adjusted gross income was over $150,000 ($75,000 if married/RDP filing separately), the prior-year option tightens. You need 110% of last year’s tax rather than 100%. Your required annual payment is the lesser of 90% of this year’s tax or 110% of last year’s.²

The Million-Dollar Rule

If your current-year California AGI reaches $1,000,000 or more ($500,000 if married/RDP filing separately), the prior-year safe harbor disappears entirely. You must base your payments on 90% of the current year’s tax. Repeating last year’s installments won’t protect you.² This catches people who have a one-off big year from a property sale or business exit, because the safe harbor they relied on in prior years isn’t there anymore.

Form 540-ES and its worksheet walk through the calculation.

Payment Schedule and Due Dates

California’s installments are not equal. Your required annual payment splits across four periods this way:

First installment, 30%, due April 15, 2026
Second installment, 40%, due June 15, 2026
Third installment, 0%, nothing due September 15, 2026
Fourth installment, 30%, due January 15, 2027

By mid-June, 70% of the year’s obligation is already due.² The dates line up with the federal estimated tax deadlines, but the percentages don’t, so keep the two calculations separate. If a due date falls on a weekend or state holiday, the deadline moves to the next business day.

If Your Income Is Uneven

The 30/40/0/30 split assumes income arrives at a steady pace. For seasonal businesses, commission earners with lumpy months, or anyone expecting a big capital gain late in the year, the annualized income installment method lets you calculate each installment based on income actually received through that date rather than a projected annual total.³

You compute it on Form FTB 5805, Sides 3 and 4, and attach the form to your annual return. If you use the annualized method for one installment period, you must use it for all four.

How to Pay

Web Pay

Web Pay is the FTB’s free online payment portal. You can schedule payments up to a year in advance through a MyFTB account or submit them as a guest.⁴ For most people this is the simplest option, and scheduling four payments at once removes the risk of forgetting a deadline.

Credit Card

Credit card payments go through ACI Payments, the FTB’s authorized processor, and carry a 2.3% service fee. On a $10,000 payment that’s $230.⁵ The fee makes it a poor default, but it’s available if you want the rewards or the float.

Check or Money Order

Mail your payment with the appropriate quarterly voucher from Form 540-ES. Make it payable to “Franchise Tax Board” and write your Social Security number or ITIN and the tax year on the check. Send it to Franchise Tax Board, PO Box 942867, Sacramento, CA 94267-0008.⁶

When Electronic Payment Becomes Mandatory

Once you make any single estimated or extension payment over $20,000, or file an original return showing total tax liability over $80,000, you are required to pay electronically from that point forward. Every subsequent payment, for any tax year and any amount, must be electronic. The payment that triggers the requirement doesn’t itself have to be electronic, but every one after it does. Noncompliance carries a 1% penalty on the payment amount.⁷

Underpayment Penalties

If your combined withholding and estimated payments fall short of the safe harbor amount by any due date, the FTB charges a penalty on the shortfall. It functions like interest, calculated on the underpaid amount for the days it stayed unpaid, at the FTB’s published estimate penalty rate. For July 1, 2025, through June 30, 2026, that rate is 7% per year.⁸

The calculation runs on each installment period separately. A shortfall in April that you make up in June costs less than one that drags on until January. In most cases the FTB figures the penalty itself and sends you a bill after you file. If you use the annualized income installment method, however, you compute the penalty on Form FTB 5805 and attach it to the return yourself.³

When No Penalty Applies

No underpayment penalty is imposed if the total tax owed for the year, after subtracting withholding and credits, is less than $500 ($250 if married/RDP filing separately).⁹

Penalty Waivers

The FTB can waive the penalty in limited situations. One is when a casualty, disaster, or other unusual circumstance caused the underpayment and charging a penalty would be inequitable. Another is when you retired after reaching age 62 or became disabled during the tax year or the year before, and the underpayment was due to reasonable cause rather than willful neglect.³

To request a waiver, check “Yes” on Part I, Question 1 of Form FTB 5805, explain the circumstances in writing, and attach supporting documentation to your return. The FTB reviews requests case by case.

Applying a Prior-Year Overpayment

If your annual return shows an overpayment, you can elect to apply some or all of it to next year’s estimated tax instead of taking a refund. The credited amount lands on your first installment of the following year. When you work through the 540-ES worksheet, reduce your calculated payment by any overpayment you’ve already applied so you don’t pay it twice.⁴ If your income later shifts, you can adjust remaining installments down, provided you still clear a safe harbor by year-end.

Disaster Postponements

After a major disaster, the FTB may postpone estimated tax deadlines for taxpayers in the affected area. For the Los Angeles County fires that began in January 2025, the FTB extended all quarterly estimated tax deadlines for LA County taxpayers to October 15, 2025, covering every installment that would otherwise have fallen due during the relief period.¹⁰

Relief usually applies automatically if your principal residence or business sits in the designated area. Taxpayers whose records are inside the zone but who are located outside it may still qualify and generally need to contact the FTB. If you get a penalty notice for a payment that fell inside a postponement window, call the number on the notice to have it reversed. Check the FTB’s website for current disaster announcements before assuming the standard calendar applies.

1
Franchise Tax Board. 2026 Instructions for Form 540-ES Estimated Tax for Individuals
2
Franchise Tax Board. Estimated Tax Payments
3
Franchise Tax Board. 2024 Instructions for Form FTB 5805
4
Franchise Tax Board. 2025 Instructions for Form 540-ES Estimated Tax for Individuals
5
Franchise Tax Board. Pay by Credit Card
6
Franchise Tax Board. Mailing Addresses
7
Franchise Tax Board. Mandatory e-Pay for Individuals
8
Franchise Tax Board. Interest and Estimate Penalty Rates
9
California Legislative Information. California Revenue and Taxation Code 19136
10
Franchise Tax Board. Los Angeles County Fires