5805F: Underpayment of Estimated Tax by Farmers and Fishermen (2025)
California · FTB · Used for tax years 2025
California Form 5805F is used by farmers and fishermen to figure their 2025 estimated tax underpayment and any resulting penalty. It also includes a section to request a penalty waiver with an explanation.
Who files this form
Form FTB 5805F is for farmers and fishermen to figure an underpayment of estimated tax and any resulting penalty for tax year 2025.
The form says to attach it to the back of Form 540, Form 540NR, or Form 541, even if you do not owe a penalty.
When it's due
For tax year 2025, the form uses these dates:
- January 15, 2026: Line 11 includes 2025 withholding taxes and estimated tax payments made on or before this date. The penalty day count on line 14 starts after this date.
- April 15, 2026: On line 13, enter the date the underpayment was paid or April 15, 2026, whichever is earlier.
The form does not state a separate filing deadline for FTB 5805F.
What you'll need
Have these records and details available:
- Your 2025 Form 540, Form 540NR, or Form 541, for tax, credits, withholding, estimated payments, and any tax on lump-sum distributions or accumulation distributions of trusts.
- Your 2024 return, if you filed one and your 2024 taxable year covered 12 months, for the prior-year tax calculation.
- Your California adjusted gross income (AGI), for the rule on line 10.
- Payment amounts and dates, including when you paid the underpayment.
- Your name as shown on the return and your SSN or ITIN.
- An explanation if you are requesting a penalty waiver on line 16.
How to file
- Complete Part I to figure your underpayment. Follow any instruction to stop if no penalty is owed.
- Complete Part II to figure the penalty, if applicable.
- Unless requesting a waiver, enter the line 15 penalty on Form 540, line 113; Form 540NR, line 123; or Form 541, line 45. Check the box on that line to show FTB 5805F is attached.
- To request a waiver, check the box on line 16 and provide an explanation. Also check the applicable box on your return.
- Attach FTB 5805F to the back of your return, even if you do not owe a penalty.
The supplied form does not give a mailing address or e-filing directions.
Common mistakes
- Leaving the form off your return because no penalty is owed. The form says to attach it even if you owe no penalty.
- Using lines 7 through 9 when they do not apply. If you did not file a 2024 return, or your 2024 taxable year was less than 12 months, skip those lines and enter line 4 on line 10.
- Overlooking the high-income rule on line 10. Use line 4 if your California AGI is at least $1,000,000, or $500,000 if married filing a separate return.
- Forgetting the return checkbox. Lines 12, 15, and 16 remind you to check the applicable box on Form 540, line 113; Form 540NR, line 123; or Form 541, line 45.
- Requesting a waiver without an explanation. Line 16 requires both a checked box and an explanation.
Questions people ask
When does Part I say no penalty is owed?
Stop if line 6 or line 9 is less than $500, or $250 if married/RDP filing separately. You also owe no penalty if line 12 is zero or less.
How is the penalty calculated?
Line 15 calculates the penalty as the number of days on line 14 divided by 365, multiplied by .07, multiplied by the underpayment on line 12.
What if I am a calendar-year taxpayer and made no estimated payment?
Line 14 says to enter 90 days.
Can I request a penalty waiver?
Yes. Check the box on line 16 and provide an explanation. Also check the applicable box on your return. The form refers to General Information E, but those instructions were not supplied here.