3800: Tax Computation for Certain Children with Unearned Income (2025)
California · FTB · Used for tax years 2025
California Form 3800 calculates tax for certain children with unearned income, including taxable interest, ordinary dividends, and capital gains. It uses the child’s income and the parent’s tax information to calculate the child’s tax and attaches only to the child’s Form 540 or
Who files this form
California Form 3800 is for certain children with unearned income, such as taxable interest, ordinary dividends, and capital gains.
For tax year 2025, the form says not to file it if the child’s unearned income is $2,700 or less. The supplied form does not give the complete eligibility rules, so income above $2,700 alone does not establish who must file.
If line 3 or line 5 is zero or less, stop completing the form but attach it to the child’s return.
What you'll need
Have these returns and details available:
- The child’s Form 540 or Form 540NR, including taxable income from line 19.
- The child’s name as shown on the return and SSN or ITIN.
- The child’s unearned income amounts and whether the child itemized deductions.
- The parent’s name, SSN or ITIN, filing status, and Form 540 or Form 540NR. The form uses the parent’s line 19 income and, for Form 540 filers, line 31 tax.
- Any Forms FTB 3800 for other children of the same parent, if applicable, to obtain their line 5 amounts.
- The tax table or tax rate schedules in the 2025 Form 540 instructions.
The form directs Form 540NR filers to additional instructions for certain tax calculations. Those instructions were not provided.
How to file
Attach Form 3800 only to the child’s Form 540 or Form 540NR.
For a child filing Form 540, enter the larger of Form 3800 line 16 or line 17 on Form 3800 line 18 and on the child’s Form 540, line 31. Check the box labeled “FTB 3800” on the child’s tax return.
Form 540NR filers are directed to the instructions for the final tax entry. The supplied text does not provide a mailing address or e-filing directions.
Common mistakes
- Attaching the form to the wrong return. Attach it only to the child’s Form 540 or Form 540NR.
- Ignoring the stop rules. Do not file the form if line 1 is $2,700 or less. If line 3 or line 5 is zero or less, stop completing it but still attach it to the child’s return.
- Counting this child’s income again on line 7. Line 7 includes only the line 5 amounts from other children’s Forms FTB 3800.
- Including FTB 3803 tax on line 10. The form specifically says not to include it.
- Forgetting the return checkbox. The form tells you to check the “FTB 3800” box on the child’s tax return.
Questions people ask
What income goes on line 1?
Enter the child’s unearned income. The form lists taxable interest, ordinary dividends, and capital gains as examples and refers you to the instructions.
What goes on line 2 if the child did not itemize deductions?
Enter $2,700. If the child itemized deductions, the form says to see the instructions, which were not provided here.
What if there is no amount on line 7?
Enter the amount from line 11 on line 13 and skip lines 12a and 12b.
Which tax amount is used on line 18?
Compare lines 16 and 17 and enter the larger amount on line 18. For Form 540 filers, also enter that amount on the child’s Form 540, line 31.