The California FTB safe harbor rules are as follows. However if 2021 AGI is much larger than 2020 AGI but you have still paid 110% of the 2020 tax due, TurboTax calculates a penalty anyway. Is this an error in TurboTax?
"If you’re required to make estimated tax payments and your prior year California adjusted gross income is more than:
- $150,000
- $75,000 if married/RDP filing separately
Then you must base your estimated tax based on the lesser of:
- 90% of your tax for the current tax year
- 110% of your tax for the prior tax year (including alternative minimum tax)
