Error in TurboTax calculation of CA 540-ES estimated taxes

Forum|Forum|1 year ago
April 5, 2025
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I underpaid my California estimated taxes for 2024 because I used TurboTax to generate the estimates, and they were clearly too low, despite the fact that I rounded the estimates up to the nearest $100. I did *not* have this problem with Federal estimates.

There's a bug in how TurboTax is calculating CA 540-ES. I am seeing others posting here with this same problem. Because of this, I received a penalty of $110 from California. Is this a known problem? Is anyone working on fixing this?

kmd11Author

Employee

The problem was that TurboTax defaults to 90% of last year's tax when it should default to 110% when preparing 540-ES estimated tax for next year. And the IRS rule is as follows:

"Individuals who are required to make estimated tax payments, and whose 2023 California adjusted gross income is more than $150,000 (or $75,000 if married/RDP filing separately) must figure estimated tax based on the lesser of 90% of their tax for 2024 or 110% of their tax for 2023 including AMT."

TurboTax should be defaulting to 110% of current year when calculating California 540-ES estimated taxes for the next year, not 90%.

TurboTax, please change your default to 110% when calculating 540-ES for California. I don't understand why the default is 110% for the Federal but not the State. Why? Please fix this.