Bug in California Form 5805 Underpayment of Estimated Tax, Part III, line 6

Forum|Forum|3 months ago
April 18, 2026
1 reply
1123 views

Using TurboTax Premier 2025 on Windows 11. All updates installed as of 4/17/2026.

Using "step-by-step," State Taxes, Other situations, Underpayment Penalty.

For question "Do you want to let the Franchise Tax Board calculate the penalty and send you a bill?", answer "No."

I entered values for last year's state taxes that don't qualify for an exception.

For question "Did you earn your income unevenly during the year?", I answered "Yes."

Eventually, get to page where you press button "Include on Return" instead of "Let FTB Bill Me." That causes TurboTax to do calculations for California Form 5805.

(BTW, prior to getting to this, there is a page that shows "Federal and California AGI Adjustments". However, these are really just California adjustments (bug).)

After giving the above answers in the step-by-step, go to Form 5805, and there is a problem in the entries for Part III, line 6.
According to FTB 5805 instructions, these deductions should be limited if,
"in any quarter federal annualized income ... is greater than:
- $504,411 (married/RDP filing jointly or qualifying surviving spouse/RDP).
- $252,203 (single or married/RDP filing separately).
- $378,310 (head of household)."
The instructions provide a worksheet for how to reduce the deductions for income greater than these values.

I found that if I entered an income above these values, the deductions were NOT reduced.
It appears that TurboTax is not using the worksheet for Part III line 6 entries.

LenaH

Employee Tax Expert

I would like to take a deeper look at this. However, I need a diagnostic file which is a copy of your tax return that has all of your personal information removed. You can send one to us by following the directions below:

TurboTax Online:

Sign into your online account.
Locate the Tax Tools on the left-hand side of the screen.
A drop-down will appear. Select Tools
On the pop-up screen, click on “Share my file with agent.”
This will generate a message that a diagnostic file gets sanitized and transmitted to us.
Please provide the Token Number that was generated in the response.

TurboTax Desktop/Download Versions:

Open your return.
Click the Online tab in the black bar across the top of TurboTax and select “Send Tax File to Agent” *
This will generate a message that a diagnostic copy will be created. Click on OK and the tax file will be sanitized and transmitted to us.
Please provide the Token Number (including the dash) that was generated in the response.

*(If using a MAC, go to the menu at the top of the screen, select Help, then, “Send Tax File to Agent”)

**Say "Thanks" by clicking the thumb icon in a post. **Mark the post that answers your question by clicking on "Mark as Best Answer"

dav321Author

Level 2

Hi Lena,

I generated the diagnostic file, and the token number is 9059977971978971-82689688 .

I want to let you know that this file reflects that in TurboTax, I went to Forms, California Form 5805, and in Part III (Annualized Income Installment Method), line 6, I overrode the entry in column (d), with what I calculated to be the correct value. Before my override, that entry was the same as line 4, column (d), which I believe to be a bug.