Form 8615 figures the kiddie tax: for children under 18, and some older students, unearned income over $2,700 is taxed at the parent's tax rate if that's higher than the child's, as of October 2026. If a child's investment income tops $2,700 and they have to file a return, Form 8615 is attached to the child's own return.
It stops families shifting investments into a child's name to use their lower tax rate. Everything below comes from the IRS's 2025 Instructions for Form 8615, checked in October 2026.
Who must file Form 8615
You file it for any child who meets all of these conditions for 2025:
- The child had more than $2,700 of unearned income.
- The child is required to file a tax return.
- The child was under 18 at the end of 2025, or was 18 and didn't have earned income of more than half their support, or was a full-time student aged 19 to 23 and didn't have earned income of more than half their support.
- At least one parent was alive at the end of 2025.
- The child doesn't file a joint return for 2025.
The rules apply whether or not the child is a dependent, and "child" includes a legally adopted child and a stepchild. Support means everything spent on food, lodging, clothing, education, medical care, recreation and transport, but a scholarship isn't counted as support if the child is a full-time student.
What counts as unearned income
- Taxable interest, dividends and capital gains, including capital gain distributions.
- Rents and royalties.
- Pension and annuity income, and the taxable part of Social Security and pension payments.
- Taxable scholarship and fellowship grants not reported on a W-2.
- Unemployment compensation, alimony, and income received as a trust beneficiary.
Earned income, such as wages from a part-time job, isn't part of the kiddie tax. It's taxed at the child's own rate.
The January 1 birthday rule
Age is tested at the end of the year, and children born on January 1 count as a year older than you'd expect. The instructions include a chart for exactly this quirk:
| Born on | Treated as, at the end of 2025 | Effect |
|---|---|---|
| January 1, 2008 | 18 | Meets the age test only if earned income wasn't more than half of support |
| January 1, 2007 | 19 | Meets it only as a full-time student without earned income over half of support |
| January 1, 2002 | 24 | Don't use Form 8615 |
Which parent's return to use
| Family situation | Use the return of |
|---|---|
| Parents married and filing jointly | The joint return |
| Married, filing separately | The parent with the greater taxable income |
| Divorced or separated, custodial parent not remarried | The custodial parent |
| Custodial parent remarried | The custodial parent and step-parent (joint return, or the higher income if separate) |
| Never married but lived together all year | The parent with the greater taxable income |
If the parent's taxable income or the other children's figures aren't known by the child's due date, the instructions suggest the child requests an extension on Form 4868. That extends the time to file, not the time to pay.
The alternative: Form 8814
A parent may be able to report a child's interest, ordinary dividends and capital gain distributions on the parent's own return using Form 8814. The child then doesn't file a return or Form 8615. The instructions warn that the tax on the child's income may be higher with this election, so it's a convenience, not a saving. It also doesn't cover other unearned income like rents.
Other taxes to watch
A child whose tax is figured on Form 8615 may also owe the 3.8% net investment income tax, figured on Form 8960, and the alternative minimum tax can apply too. Brokerage sales that create the gains are on Form 1099-B.
Filling it in
- Enter the parent's name, Social Security number and filing status on lines A to C.
- Line 1: the child's unearned income. Line 2: $2,700, or if the child itemizes, the larger of $2,700 or $1,350 plus the itemized deductions directly connected with that income.
- Work out the child's net unearned income, then the tax at the parent's rate on the worksheets.
- Compare with the tax at the child's rate and use the higher result on the child's return.
Common Form 8615 mistakes
- Counting a child's wages towards the $2,700. Only unearned income counts.
- Using the wrong parent's return after a divorce or remarriage. The instructions set an order, starting with the custodial parent.
- Missing the support test for 18-year-olds and students. Earned income of more than half of support takes them out of Form 8615.
- Electing Form 8814 for a child with rental or other unearned income it doesn't cover.
The verdict
If a child's investment income stays at $2,700 or less, Form 8615 doesn't apply. Above that, the extra is taxed at the parent's rate, so putting investments in a child's name saves less than people expect. Check the age rules carefully for 18-year-olds and students, and only choose the Form 8814 shortcut if the convenience is worth a possibly higher bill.
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Frequently asked questions
What is the kiddie tax threshold for 2025?
Form 8615 applies when a child has more than $2,700 of unearned income and meets the other conditions.
Does Form 8615 apply to a child's wages?
No. Earned income such as wages is taxed at the child's own rate. Form 8615 applies to unearned income.
Up to what age does the kiddie tax apply?
Under 18, 18 if earned income wasn't more than half of support, or a full-time student aged 19 to 23 under the same support test.
Which parent's tax rate is used on Form 8615?
For married parents filing jointly, the joint return. For other situations, generally the parent with the greater taxable income or the custodial parent, as the instructions set out.
Can a parent report a child's income instead?
A parent may be able to report a child's interest, ordinary dividends and capital gain distributions on Form 8814, though the tax may be higher.
Does Form 8615 apply if the child is a stepchild?
Yes. For these rules, the term child includes a legally adopted child and a stepchild, whether or not the child is a dependent.
What if I don't know the parent's figures by the deadline?
The instructions say the child should request an extension with Form 4868. That extends the time to file, not the time to pay.
