IRS Form 8615 is the tax form you use to figure the tax on a child’s unearned income when that income is more than a yearly limit set by the IRS. For tax year 2025, that limit is $2,700, and for tax year 2026, it is $2,800 because of inflation, according to the Form 8615 instructions and Rev. Proc. 2024-40. The form applies the kiddie tax under Internal Revenue Code §1(g), which taxes part of a child’s investment income at the parent’s higher tax rate.
The kiddie tax stops parents from shifting investment income to children to dodge higher tax brackets. About 4.8 million dependent children reported unearned income on recent IRS data, and a large share of them owed kiddie tax. Filing Form 8615 wrong can mean back taxes, penalties under IRC §6651, and interest that grows fast.
In this guide, you will learn:
- 📋 Who must file Form 8615 and the three tests every child must meet
- 🧮 How to compute the tax line by line, with named examples
- ⚖️ When Form 8814 is a smarter pick than Form 8615
- 🚫 The seven biggest mistakes filers make and how to avoid each one
- 🗺️ How states like California, New York, and others treat the kiddie tax differently from federal rules
Who Must File IRS Form 8615
A child files Form 8615 only when three tests in the official IRS instructions all apply for the same tax year. The form is for the child’s return, not the parent’s return. Parents who want to skip the child’s return entirely may instead use Form 8814, but that choice has trade-offs covered later. The kiddie tax rules sit inside IRC §1(g) and were last reset by the SECURE Act of 2019.
The three tests below must all be true. Miss one, and Form 8615 is not required. Get one wrong, and the IRS may bill you with a CP2000 notice months later.
Test 1: The Unearned Income Threshold
The child’s unearned income must be more than $2,700 for 2025 or $2,800 for 2026, per the IRS inflation adjustments. Unearned income means interest, dividends, capital gains, rents, royalties, taxable scholarships, and trust or annuity income. The plain-English idea is that money the child did not work for triggers the rule. The consequence of ignoring this test is that unreported unearned income still owes tax at the parent’s rate, plus interest and possible accuracy penalties under IRC §6662.
A real example helps. Maya, age 14, received $4,200 in dividends from a custodial brokerage account in 2025. Her unearned income tops $2,700, so she meets Test 1. A common misconception is that small amounts are safe; in truth, even one extra dollar above the threshold can put a child into Form 8615 territory.
Test 2: Age Requirements
The child must be under age 18 at year-end, OR age 18 with earned income that is not more than half their support, OR a full-time student aged 19–23 with earned income that is not more than half their support. The IRS Publication 929 explains support as housing, food, education, medical, transport, and recreation costs. The reason for the wide age band is to stop college-age dependents from being a tax shelter for parents.
Take Diego, a full-time sophomore who turned 20 in 2025 and earned $9,000 from a summer job while his parents paid $30,000 of his support. His earned income is far below half of his support, so he meets Test 2. The consequence of misreading the support test is that parents may wrongly assume the kiddie tax stops at 18 and skip the form, leading to under-reported tax later.
Test 3: At Least One Living Parent
At least one of the child’s parents must be alive at year-end, per the Form 8615 instructions. The rule exists because Form 8615 keys off a parent’s tax rate, so an orphan has no parental rate to borrow. The consequence of failing this test is that the child files a normal Form 1040 with their own bracket; no kiddie tax applies.
A common misconception is that step-parents do not count. They can. If the custodial parent is remarried and files jointly, the step-parent’s income flows into the calculation through the joint return.
Filing Status and Dependents
The child must also be required to file a return and cannot file a joint return with a spouse for the year. Most kiddie-tax kids are dependents on a parent’s return, but Form 8615 does not require dependent status; it requires the three tests above. The consequence of a married child filing jointly is that Form 8615 is off the table, even if the unearned income is large.
Form 8615 vs. Form 8814: Which to Use
Parents face a choice when a child has only interest, dividends, and capital gain distributions: file Form 8615 with a child return, or elect Form 8814 and pull the income onto the parent’s Form 1040. Each path has costs.
| Decision Factor | Form 8615 (Child Files) |
|---|---|
| Income types allowed | All unearned income, including capital gains from sales |
| Income cap | No upper cap |
| Tax rate applied | Child’s bracket up to threshold, parent’s marginal rate above |
| Recordkeeping | Child needs own return, schedules, and records |
| AGI impact on parents | None |
| State conformity | Generally follows federal under state tax codes |
| Decision Factor | Form 8814 (Parent Elects) |
|---|---|
| Income types allowed | Only interest, dividends, and capital gain distributions |
| Income cap | $13,500 in 2025 per the Form 8814 instructions |
| Tax rate applied | Flat add-on tax plus parent’s bracket on excess |
| Recordkeeping | One return; child files nothing |
| AGI impact on parents | Raises parent AGI, can hurt phase-outs and credits |
| State conformity | Some states do not allow the election |
The plain-English takeaway is that Form 8814 is simpler but often more expensive once parent phase-outs are counted. Form 8615 takes more work but usually saves real money. The consequence of picking Form 8814 without modeling parent phase-outs is lost credits like the American Opportunity Credit and the Saver’s Credit.
A Quick History of the Kiddie Tax
The kiddie tax began with the Tax Reform Act of 1986 to stop income shifting through custodial accounts. Originally, only children under 14 were covered. Congress raised the age to under 18 in 2006, and again to under 24 for full-time students in 2007 under the Small Business and Work Opportunity Tax Act.
The Tax Cuts and Jobs Act of 2017 changed the math by taxing kiddie unearned income at trust and estate rates, which spike at $12,500 of income. That hurt families of fallen service members, called Gold Star families, whose kids received survivor benefits taxed sharply. Congress fixed the issue in the SECURE Act of 2019, which restored the parent-rate method retroactive to 2018.
The plain-English point is that the modern Form 8615 again uses the parent’s marginal rate. The consequence of ignoring this history is that older guides still describe the trust-rate method, which the IRS retired. A common misconception is that filers can pick the better method between the two; they cannot, and the Form 8615 instructions make the parent-rate method the only path.
Documents and Inputs You Need Before You Start
Gather every document below before opening Form 8615. Each piece feeds a specific line on the form, and missing data is the leading cause of amended returns under Form 1040-X.
- The child’s Form 1040, already prepared through line 15
- All Forms 1099-INT, 1099-DIV, 1099-B, and Schedule K-1
- The child’s Schedule D if there were capital gains from sales
- The parent’s filed Form 1040 for the same year
- The parent’s Schedule D Tax Worksheet or Qualified Dividends and Capital Gain Tax Worksheet
- The standard deduction for dependents from the IRS standard deduction tables
- A list of any other children of the same parent who must also file Form 8615
The consequence of starting without the parent’s finished return is a recompute, because Form 8615 borrows the parent’s taxable income and tax. A real example is Priya, who filed her son’s return in February before her own; she had to amend the son’s return in April, paying $58 in interest.
Line-by-Line Walkthrough of Form 8615 (2025)
This walkthrough follows the official 2025 Form 8615 and its instructions. Numbers are for the 2025 tax year; for 2026, replace $2,700 with $2,800 and $1,350 with $1,400 per the Rev. Proc. 2024-40 and Rev. Proc. 2025-32 inflation tables.
Part I: Child’s Net Unearned Income
Line 1 — Child’s Unearned Income
Add up interest, dividends, capital gains, taxable scholarships, and other unearned income. Use the totals from Schedule B and Schedule D. The plain-English rule is if it was not earned by working, it goes on Line 1. The consequence of missing items, like a small 1099-DIV from a forgotten DRIP, is an IRS matching notice months later.
A common misconception is that tax-exempt interest belongs here; it does not. Munis stay off Form 8615, though they may matter for the Net Investment Income Tax on the parent’s return.
Line 2 — Standard Threshold
Enter $2,700 for 2025 unless the child itemizes directly connected investment expenses, which is rare since the TCJA suspended most miscellaneous itemized deductions through 2025. The number equals two times the dependent’s base standard deduction of $1,350. The consequence of guessing the wrong year’s threshold is overpaying or underpaying tax. A common misconception is that the threshold is the same as the child’s standard deduction; it is double the dependent base.
Line 3 — Subtract Line 2 from Line 1
This step isolates the net unearned income exposed to kiddie tax. If Line 1 is $4,200 and Line 2 is $2,700, then Line 3 is $1,500. The consequence of a math slip here is a wrong tax for every line that follows.
Line 4 — Child’s Taxable Income
Pull this number from the child’s Form 1040 line 15. It includes both earned and unearned income minus the child’s standard deduction. The plain-English idea is that Line 4 is the full pie before we slice out the kiddie portion. The consequence of using adjusted gross income by mistake is overstating the child’s tax base.
Line 5 — Smaller of Line 3 or Line 4
The IRS taxes the lesser number at the parent’s rate. This protects kids whose taxable income is smaller than their net unearned income because of itemized deductions or losses. The consequence of skipping the smaller-of test is paying parent-rate tax on income the child does not actually have.
Part II: Tentative Tax at Parent’s Rate
Line 6 — Parent’s Taxable Income
Copy from the parent’s Form 1040 line 15. For married parents filing separately, use the higher-income parent under the Form 8615 instructions. For divorced parents, use the custodial parent. The consequence of using the wrong parent is an audit risk and a recompute.
A real example is Aiden, whose divorced parents disagreed about who was custodial. The IRS uses the parent with whom the child lived for the greater part of the year, per IRC §152(e).
Line 7 — Net Unearned Income of Other Children
Add the Line 5 amounts from every other child of the same parent who also files Form 8615. The rule stops families from spreading income across kids to dodge higher brackets. The consequence of forgetting a sibling’s Line 5 is under-paying federal tax for both kids.
Line 8 — Total
Add Lines 5, 6, and 7. This is the combined taxable base for parent-rate calculations. The plain-English idea is to pretend the kiddie income sits on top of the parent’s income for one calculation. The consequence of math errors here ripples through Lines 9–13.
Line 9 — Tax on Line 8 at Parent’s Rate
Compute tax on Line 8 using the parent’s filing status and the 2025 tax tables or Tax Computation Worksheet. If the parent had qualified dividends or long-term capital gains, use the Qualified Dividends and Capital Gain Tax Worksheet or Schedule D Tax Worksheet. The consequence of using ordinary brackets when capital gains apply is a tax overpayment that the IRS will not catch and refund automatically.
Line 10 — Parent’s Tax
Copy the parent’s Form 1040 tax line. This is the parent’s tax without any of the children’s kiddie income. The plain-English point is that we will subtract this baseline next to find the added tax caused by the children. The consequence of grabbing total tax including credits is a wrong subtraction.
Line 11 — Subtract Line 10 from Line 9
The difference is the extra tax the parent’s bracket would owe on the combined kiddie income. The consequence of a negative number is rare and means a calculation error somewhere above.
Line 12a and 12b — Allocation Among Siblings
If multiple children file Form 8615 from the same parent, divide Line 11 across the kids by the ratio of each child’s Line 5 to total sibling Line 5. The plain-English idea is each kid pays a fair slice of the family’s added tax. The consequence of skipping the allocation is double-counting tax across siblings.
Line 13 — Child’s Share of Parent-Rate Tax
This is Line 11 multiplied by Line 12b. It is the child’s kiddie portion of tax. A common misconception is that this is the final tax; it is one of two pieces compared in Part III.
Part III: Child’s Tax — The Larger of Two Methods
Line 14 — Subtract Line 5 from Line 4
The result is the part of the child’s taxable income that stays at the child’s own rate. The consequence of a sign error is over-taxing the child.
Line 15 — Tax on Line 14 at Child’s Rate
Use the 2025 Tax Tables or worksheet for the child’s filing status (almost always single). If the child had qualified dividends or long-term capital gains in this slice, use the Qualified Dividends and Capital Gain Tax Worksheet. The consequence of using a worksheet you do not need is wasted time, while skipping a needed worksheet means an overpayment.
Line 16 — Add Lines 13 and 15
This is the kiddie tax method total. It mixes parent-rate tax on the kiddie portion with child-rate tax on the rest.
Line 17 — Tax on Line 4 at Child’s Rate Only
Compute tax as if the child had no kiddie tax at all, using only the child’s own rate on the full Line 4. The plain-English idea is what tax would the child pay without the kiddie rule?
Line 18 — The Larger of Line 16 or Line 17
Enter the larger number on Form 1040 line 16. The IRS makes you pay the higher of the two methods. The consequence of taking the smaller number is an underpayment notice plus penalties under IRC §6651.
Worked Example 1: Maya, the 14-Year-Old Investor
Maya is 14, a dependent of married parents filing jointly. In 2025 she received $4,200 in ordinary dividends from a custodial Vanguard account and earned $0 from work. Her parents had $180,000 of taxable income.
- Line 1: $4,200
- Line 2: $2,700
- Line 3: $1,500
- Line 4: Maya’s taxable income = $4,200 − $1,350 standard deduction = $2,850
- Line 5: Lesser of $1,500 or $2,850 = $1,500
- Line 6: $180,000
- Line 7: $0 (only child)
- Line 8: $181,500
- Line 9: Tax at MFJ rate on $181,500 ≈ $30,930 per 2025 brackets
- Line 10: Tax at MFJ rate on $180,000 ≈ $30,570
- Line 11: $360
- Line 13: $360
- Line 14: $1,350
- Line 15: Tax at single rate on $1,350 ≈ $135
- Line 16: $495
- Line 17: Tax at single rate on $2,850 ≈ $285
- Line 18: $495 (larger)
Maya owes $495 of federal tax instead of $285 because of the kiddie tax. The consequence of skipping Form 8615 would be a CP2000 for the $210 difference plus interest.
Worked Example 2: Diego, the Full-Time College Student
Diego is 20 and a full-time sophomore. In 2025 he earned $9,000 from a summer job and received $6,500 in long-term capital gains from selling shares his grandparents gave him. His parents had $260,000 of taxable income.
- Line 1: $6,500
- Line 2: $2,700
- Line 3: $3,800
- Line 4: ($9,000 + $6,500) − $15,000 standard deduction (capped at earned income + $450, so $9,450) = $6,050
- Line 5: Lesser of $3,800 or $6,050 = $3,800
- Line 6: $260,000
- Line 8: $263,800
- Line 9–11: Marginal 24% bracket applies; added tax ≈ $912
- Line 13: $912
- Line 14: $2,250
- Line 15: $0 because long-term capital gain at 0% bracket per IRS capital gains rates
- Line 16: $912
- Line 17: $605
- Line 18: $912
Diego learns that grandparents’ gifted stock cost him $307 more than expected. A common misconception is that long-term capital gains escape kiddie tax; they do not, although they keep their preferential rate inside Line 9 with the Schedule D Tax Worksheet.
Worked Example 3: Aiden, Child of Divorced Parents
Aiden is 12 and lives with his mother nine months a year. His mother’s taxable income is $58,000; his father’s is $190,000. Aiden has $5,400 of bond interest.
- Line 1: $5,400
- Line 2: $2,700
- Line 3: $2,700
- Line 4: $5,400 − $1,350 = $4,050
- Line 5: $2,700
- Line 6: Use mother’s $58,000 because she is custodial under IRC §152(e)
- Line 8: $60,700
- Line 9–11: Added tax at 22% bracket ≈ $594
- Line 13: $594
- Line 14: $1,350
- Line 15: $135
- Line 16: $729
- Line 17: $405
- Line 18: $729
The consequence of using the father’s higher income would have been an over-tax of about $400. The plain-English point is that the custodial-parent rule can save real money in split-custody cases.
Three Real-World Scenarios and Their Outcomes
| Family Situation | Tax Result Under Form 8615 |
|---|---|
| Teen with $5,000 of dividends in custodial UTMA, parents in 32% bracket | Net unearned income above $2,700 taxed at 32%, costing roughly $736 extra |
| College senior age 22 with $20,000 trust distribution, parents in 24% bracket | $17,300 taxed at 24%, kiddie tax adds about $4,152 over child-only rates |
| Gold Star child receiving $15,000 in survivor annuity, single parent in 12% bracket | Parent-rate method under SECURE Act saves about $2,800 vs. old trust-rate method |
| Mistaken Move by Family | Consequence the IRS Imposes |
|---|---|
| Skipping Form 8615 because child’s income seems small | Notice and back tax under IRC §6651 |
| Using Form 8814 when child has capital gains from sales | Election denied; amended returns required |
| Filing child’s return before parent’s | Recompute and possible interest charges |
| Smart Move by Family | Benefit Earned |
|---|---|
| Holding appreciated stock until child is 24+ | Avoids kiddie tax entirely under IRC §1(g) |
| Using a 529 plan instead of UTMA for college savings | Earnings grow tax-free for qualified costs |
| Harvesting losses in the child’s account before year-end | Lowers Line 1 unearned income and may eliminate kiddie tax |
Mistakes to Avoid on Form 8615
- Forgetting to file when capital gains push income over the threshold. A single big sale can spike Line 1, and the consequence is the IRS issuing a CP2000 notice up to three years later.
- Using last year’s threshold. The Rev. Proc. 2024-40 bumped 2025 to $2,700; using $2,600 from 2024 leads to under-tax.
- Picking the wrong parent on Line 6. Custodial parent rules under IRC §152(e) decide this, not whoever earns more.
- Ignoring sibling Form 8615s on Line 7. Multiple kids must combine net unearned income, or both returns are wrong.
- Treating tax-exempt interest as unearned income. Munis are not on Line 1; the consequence is overstating tax.
- Skipping the Qualified Dividends Worksheet. Capital gains keep their lower rate even inside Form 8615.
- Filing the child’s return before the parent’s. The parent’s tax must be final first.
- Using Form 8814 when income exceeds $13,500. The election is barred by the Form 8814 instructions.
- Forgetting the Net Investment Income Tax. A child with high unearned income may owe an extra 3.8%.
- Missing state-level kiddie tax rules. California has its own Form 3800, and skipping it leads to state notices.
Do’s and Don’ts
- Do finalize the parent’s return first so Lines 6 and 10 are accurate.
- Do use the Schedule D Tax Worksheet when capital gains are present, because it preserves the 0% or 15% rate.
- Do check the child’s age as of December 31 against the three age tests in IRS Publication 929.
- Do keep the original Forms 1099 for at least three years per IRC §6501.
- Do model both Form 8615 and Form 8814 before choosing, because parent phase-outs change the answer.
- Don’t assume the kiddie tax ends at age 18; full-time students can face it through age 23.
- Don’t confuse earned and unearned income; wages from a real job do not trigger kiddie tax.
- Don’t file paper forms if e-file is available, since e-file catches Line 5 math errors.
- Don’t forget state filing duties; many states piggyback on federal kiddie tax.
- Don’t ignore estimated taxes; large unearned income can require quarterly payments.
Pros and Cons of Form 8615 vs. Form 8814
- Pro of 8615: Captures all unearned income, including capital gains from sales, with no $13,500 cap.
- Pro of 8615: Keeps parent AGI clean, protecting credits like the Child Tax Credit phase-in.
- Pro of 8615: Lets the child build a tax filing history useful for credits later.
- Pro of 8615: Allows long-term capital gains to keep the 0% or 15% rate.
- Pro of 8615: Required when income tops $13,500, so families with growth get correct treatment.
- Con of 8615: Requires a separate return for the child with its own complexity.
- Con of 8615: Demands a finalized parent return before the child return can finish.
- Con of 8615: Multiplies paperwork when several siblings have unearned income.
- Con of 8615: Increases audit-touch points across two returns.
- Con of 8615: Adds preparer cost, often $150 to $400 according to NATP fee surveys.
State-Level Nuances
Most states with an income tax start from federal taxable income or AGI, so they pull in Form 8615 results automatically, per the Federation of Tax Administrators. Yet states differ on three things: rate conformity, separate forms, and Form 8814 acceptance. The plain-English idea is that you cannot trust federal rules to fully cover your state.
California requires its own Form FTB 3800 to apply parent-rate kiddie tax for state purposes, and it does not accept the federal Form 8814 election; parents must file FTB 3803 instead. New York follows federal taxable income but uses its own marginal rates. Texas, Florida, and other states without income tax have no kiddie tax. The consequence of skipping a state form is state penalties under each state’s own version of the federal accuracy-related rules.
Recap of Key Court and IRS Rulings
The Tax Court has weighed in on Form 8615 several times. In Pang v. Commissioner, T.C. Summary 2017-13, the court held that a custodial-parent designation under IRC §152(e) controls Line 6 even when the non-custodial parent claims the dependency exemption. The plain-English point is that custody, not exemption, drives the kiddie rate.
In Notice 2018-83, the IRS clarified that survivor benefits from the Department of Defense qualify as unearned income, which led directly to the SECURE Act fix. The consequence for Gold Star families before the fix was crushing trust-rate tax; the consequence after the fix is parent-rate tax that is usually much lower.
The IRS Chief Counsel Advice 202017027 addressed taxable scholarships and confirmed they count as unearned income for Form 8615, even though they count as earned income for the dependent’s standard deduction. The plain-English point is that one number can wear two hats. A common misconception is that scholarships always escape kiddie tax; they do not.
Filing Tips and Deadlines
The standard deadline for Form 8615 is the same as the child’s Form 1040, normally April 15 of the year after the tax year. An automatic six-month extension is available with Form 4868, but tax owed is still due by April 15. The consequence of late payment is failure-to-pay penalty under IRC §6651(a)(2), generally 0.5% per month.
Electronic filing is allowed for Form 8615 through every major tax program and through the IRS Free File system if income limits are met. The plain-English idea is that e-file catches more math errors than paper filing. A real example is Priya, who used Free File and caught a Line 5 mismatch before submitting; the consequence of paper filing for her would have been a four-month IRS letter cycle.
FAQs
Does my child have to file Form 8615 if their income is only $2,500?
No. The 2025 threshold is $2,700, so unearned income of $2,500 does not trigger Form 8615 under the IRS Form 8615 instructions, although the child may still need to file a normal return.
Is Form 8615 required for a 19-year-old who works full-time?
No. A 19-year-old whose earned income covers more than half of their support is not subject to the kiddie tax under IRS Publication 929, so Form 8615 is not required.
Can I avoid Form 8615 by gifting stock to a 24-year-old child?
Yes. Children age 24 and older are outside the kiddie tax under IRC §1(g), so gifts to them are taxed at their own rate, not the parent’s.
Does long-term capital gain still get the lower rate inside Form 8615?
Yes. The Schedule D Tax Worksheet preserves 0%, 15%, or 20% capital gains rates even when computing kiddie tax on Lines 9 and 15.
Can divorced parents pick whichever rate is lower?
No. The Form 8615 instructions require the custodial parent under IRC §152(e), not the parent with the lower rate.
Is taxable scholarship money subject to Form 8615?
Yes. Per Chief Counsel Advice 202017027, taxable scholarship amounts count as unearned income for kiddie tax even though they count as earned income for the standard deduction.
Can I use Form 8814 if my child has a $20,000 capital gain from selling stock?
No. Form 8814 only allows interest, dividends, and capital gain distributions, and it caps total income at $13,500 for 2025.
Does the kiddie tax apply if both parents are deceased?
No. Test 3 of Form 8615 instructions requires at least one living parent, so an orphan files a normal Form 1040 without kiddie tax.
Is unearned income from a 529 plan subject to Form 8615?
No. Qualified 529 plan distributions are tax-free, and only non-qualified distributions trigger income, which is taxed to the recipient under IRC §529.
Can my child claim the standard deduction and still owe kiddie tax?
Yes. The dependent standard deduction reduces Line 4 but not Line 1, so the child can still owe kiddie tax under IRS Publication 501 deduction rules.
Does Form 8615 apply to a married 17-year-old filing jointly?
No. A child filing a joint return is excluded from kiddie tax by the Form 8615 instructions, regardless of unearned income.
Will my child owe Net Investment Income Tax on top of kiddie tax?
Yes. A child whose modified AGI exceeds $200,000 may owe an extra 3.8% under the Net Investment Income Tax, separate from Form 8615.
Does California follow federal Form 8615 rules exactly?
No. California uses its own Form FTB 3800 and rejects the federal Form 8814 election, requiring a separate state-level kiddie tax computation.
Related reading
- Does Kiddie Tax Apply to 18-Year-Olds? (w/Examples) + FAQs
- How to File a Kiddie Tax Return in TurboTax (w/Examples) + FAQs
- How to Avoid the Kiddie Tax (w/Examples) + FAQs
- Does Kiddie Tax Go on Parents’ Return? (w/Examples) + FAQs
- How to Fill Out IRS Form 8814 (w/Examples) + FAQs
- How to Fill Out IRS Form 8815 (w/Examples) + FAQs
- How to Qualify for Child Tax Credit (w/Examples) + FAQs