After finishing my California taxes, the Summary showed a late penalty for underpayment of tax. I was careful to be sure I withheld at least 110% of what my 2023 tax amount to avoid this penalty so I was surprised. Checking Form FTB 5805 I see that TurboTax did not fill out Part II line 5 which shows my 2023 tax liability even though I had imported my 2023 Turbo Tax tax information. I filled in the amount in the form and the penalty went away.
Moral of the story is if you get a late penalty on your California taxes, check Form 5805 Part II Line 5 to see if it is filled out.
