California state income tax

Primary form: Form 540

State tax in BasilTax: Yes — we calculate it for you

Structure: bracket

Includes Mental Health Services surtax on high earners.

Verify your return

Upload your W-2s and 1099s, assign them to a return, and run compute. For states we support end-to-end, BasilTax applies that state’s own rules—brackets, deductions, and the usual quirks—so your state tax lines up with your federal return.

Why verification matters →

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