California Estimated Tax — Q1 April 15

Who must file or pay

California residents and businesses with California source income expecting to owe $500+ in California income tax ($250 for MFS). California requires 30% of estimated tax with the first payment.

What you need to know

California has a unique estimated tax installment schedule that confuses many taxpayers. Instead of four equal payments, California requires:

- Q1 (due April 15): 30% of estimated annual liability - Q2 (due June 15): 40% of estimated annual liability - Q3 (due October 15): 0% — no payment required - Q4 (due January 15): 30% of estimated annual liability

This front-loaded schedule means California's Q2 payment is the largest, and there is no September payment (unlike federal). California also does NOT conform to federal safe harbor rules — the CA safe harbor is 100% of prior-year CA tax liability regardless of prior-year income level.

California does not conform to many federal tax provisions: no federal bonus depreciation (§168k), no federal qualified opportunity zone exclusion, and the CA standard deduction ($5,202 single / $10,404 MFJ for 2024) is significantly lower than the federal amount.

California underpayment penalty is 5% of the underpayment on each installment. Note: California's installment schedule is different from federal — CA requires 30%/40%/0%/30% (Q1/Q2/Q3/Q4), not the federal 25%/25%/25%/25%.

Required forms

• →Form 540-ES
• →FTB payment portal

Go deeper

A licensed TaxosAgent professional reviews your situation before this deadline — so you maximize savings, not just compliance.