Who Has Tax Liability in a Custodial Account? 2026 IRS Rules

The person who has tax liability in a custodial account is the child, every time, without exception. A UGMA or UTMA account is an irrevocable transfer of assets to a minor: the money belongs to the child the moment it lands in the account, and so does the tax bill. What confuses most families is not the ownership rule, but the filing mechanics and the Kiddie Tax, which can cause a portion of that income to be taxed at the parent's marginal rate. This guide isolates who legally owes the tax from who files the paperwork and walks through the three-tier income stack that determines what rate applies at each dollar level.

Key takeaways

• The child is always the legal taxpayer for custodial account income, UGMA and UTMA assets are irrevocably the minor's property under all state laws.
• The custodian has zero personal tax liability; their role is fiduciary management and filing returns on behalf of the minor.
• The Kiddie Tax (IRC Section 1(g)) applies the parent's marginal rate only to unearned income above the $2,700 threshold, not to the entire account balance.
• Filing mechanics (Forms 8615 and 8814) do not shift legal liability, even when the parent reports the child's income on their own return, the child remains the taxpayer.
• Once the child ages out of the Kiddie Tax (generally at 18 with sufficient earned income, or 24 regardless), all unearned income is taxed at the child's own rate.

The Core Rule: The Child Owns the Account, and the Tax Bill

UGMA (Uniform Gifts to Minors Act) and UTMA (Uniform Transfers to Minors Act) accounts share one unshakable rule: the assets are irrevocably the minor's property. The moment a parent, grandparent, or any donor transfers cash or securities into a custodial account, legal ownership passes to the child. The donor cannot take the money back. The custodian manages it, choosing investments, executing trades, making withdrawals for the child's benefit, but holds zero beneficial interest.

This ownership structure determines tax liability with absolute clarity. The child is the legal taxpayer because the child owns the assets. The IRS treats custodial account income exactly like income earned by the child from any other source: it belongs on the child's tax return unless a specific election (Form 8814) lets the parent report it on theirs. Even then, the underlying liability stays with the child.

A point most articles blur: "who files" and "who owes" are distinct questions. A parent signs the return for a 12-year-old who cannot legally file alone. The parent may even report the income on their own Form 1040. But the tax liability is the child's, if there is an underpayment, the IRS pursues the child's tax identification number, not the parent's. The custodian's name on the account statement confuses people further. The custodian is simply a fiduciary, no different in principle from a trustee who manages assets they do not own.

UGMA vs. UTMA: Does the Account Type Change Who Owes?

UGMA and UTMA accounts operate under different state statutes, but neither difference changes who owes the tax. UGMA, adopted in most states starting in 1956, limits allowable assets to cash, securities, and insurance policies. UTMA, enacted later and now the law in every state except South Carolina and Vermont (the remaining UGMA-only states), expands allowable assets to include real estate, art, patents, and royalties.

The tax treatment is identical under both statutes. Income generated inside the account, dividends, interest, capital gains distributions, is the minor's unearned income, reportable under the same IRS rules regardless of whether the account carries a UGMA or UTMA label. The only practical difference that touches taxes is the age of termination: UTMA states typically allow the custodian to delay transfer until age 21 or even 25 in some states, while UGMA states generally require transfer at 18. A later termination age means the Kiddie Tax may apply longer, since the assets remain in the child's name under custodial control.

Custodian vs. Taxpayer: Two Different Roles

The custodian is not the taxpayer. This distinction trips up many families because the custodian's name appears on the account, the custodian receives the 1099 forms, and the custodian controls all transactions. But the IRS looks through the custodial wrapper to the beneficial owner, the child, whose Social Security number is tied to the account from day one.

A custodian has exactly one tax-related duty: ensuring returns are filed correctly. If income exceeds the filing threshold, the custodian must either file a return on the child's behalf or assist the parent in making a Form 8814 election. The custodian never pays tax on custodial account income from their own pocket. Using custodial funds for a purpose that does not benefit the child is a breach of fiduciary duty under state law, potentially actionable by the child upon reaching majority, but the tax liability for income the account generated before that misuse still rests with the child.

How the IRS Splits Custodial Account Income Into Three Tiers

When a custodial account generates unearned income, dividends from stock, interest from bonds, capital gains from mutual fund distributions, the IRS applies a three-tier structure to determine how much is taxable and at what rate. This is the mechanism most readers are actually searching for when they ask about tax liability in a custodial account: not who owns the bill in theory, but how much of the income gets taxed at the parent's higher rate.

Ce système en trois niveaux est crucial pour comprendre qui paie les impôts sur un compte de garde et à quel taux.

The Kiddie Tax, codified at IRC Section 1(g), creates this tiered system. Congress enacted it to close a loophole: wealthy parents shifting investment assets to children in low brackets to slash the family's overall tax bill. The three tiers work as a stack, each dollar of unearned income falls into one tier based on how much total unearned income the child received during the year.

IRS Publication 929 (Tax Rules for Children and Dependents) provides the official guidance on these thresholds, which the IRS adjusts annually for inflation. For tax year 2026, the estimated thresholds, pending the IRS's formal inflation update, are $1,350 for each of the first two tiers, making the Kiddie Tax trigger point around $2,700 in total unearned income (IRS, 2025).

Tier 1: The Tax-Free Slice

The first $1,350 of a dependent child's unearned income is effectively tax-free. This is not a separate exemption, it is the portion of the child's standard deduction that can offset unearned income.

For a dependent child who does not file a joint return, the standard deduction is the greater of (a) $1,350 or (b) earned income plus $450, capped at the regular standard deduction for a single filer. In a custodial account context, where the minor typically has no earned income, the standard deduction equals $1,350. Every dollar of unearned income up to that amount is sheltered, zero federal income tax. Most modest custodial accounts never cross this threshold, which explains why many families with small UGMA balances never file returns for their children.

Tier 2: The Child's Own Rate

The next $1,350 of unearned income falls into a layer taxed at the child's own marginal rate. For most minors, this means the 10% bracket applies to the first taxable dollars, then 12%, and so on, though in practice, custodial account income rarely pushes a child beyond the lowest brackets.

Even at 10% or 12%, this tier is favorable compared to a parent's rate. A parent in the 24% bracket would pay $324 on $1,350 of income; the same income taxed at the child's 10% rate costs $135. This spread is modest, but it represents the legitimate tax benefit of custodial accounts, the window the Kiddie Tax was designed to narrow, not eliminate entirely.

Tier 3: Where the Parent's Rate Kicks In (the Kiddie Tax)

Once unearned income exceeds $2,700, the Kiddie Tax engages. Every dollar above this combined threshold, Tier 1 plus Tier 2, is taxed at the parent's marginal rate, not the child's rate. This is the top slice of the income stack.

If a parent is in the 32% federal bracket, income above $2,700 gets taxed at 32% on the child's return. The parent does not receive a separate bill; the tax is computed on Form 8615, attached to the child's own Form 1040, using a rate lookup tied to the parent's taxable income. This is where the Kiddie Tax earns its name: the child's tax bill grows as if the parent had earned the income directly.

For 2026, the estimated threshold that triggers the parent's-rate tier is $2,700 (IRS, 2025). The exact figure will be released when the IRS publishes its annual inflation adjustments, typically in late 2025 or early 2026.

Worked Example: Calculating Tax Liability Step by Step

Take a concrete scenario to make the three-tier stack visible. A 14-year-old named Adam holds a UTMA account funded years ago by his grandparents. The account contains a diversified portfolio of mutual funds and individual stocks. During 2026, the account generates $5,500 in unearned income: $2,000 in qualified dividends, $1,200 in ordinary dividends, $1,800 in long-term capital gains distributions, and $500 in short-term capital gains distributions.

Adam has no earned income. His parents file jointly with taxable income placing them in the 24% marginal bracket for ordinary income and the 15% bracket for qualified dividends and long-term capital gains.

The goal is to trace every dollar to its correct tier and determine the tax bill, and who bears it.

Setting Up the Scenario

Adam's total unearned income is $5,500. Against this, his standard deduction of $1,350 applies first.

Tier 1 outcome: The first $1,350 is fully sheltered. Tax owed on this slice: $0.

After absorbing the deduction, $4,150 of unearned income remains taxable ($5,500 minus $1,350). The next step sorts it into Tier 2 (child's rate) and Tier 3 (parent's rate via Kiddie Tax).

Tier 2 absorbs the next $1,350. Taxable at Adam's own rate: $1,350 × 10% = $135.

Tier 3 captures everything above $2,700: $4,150 minus $1,350 already assigned to Tier 2 = $2,800. This $2,800 is taxed at the parent's marginal rates, but the rate depends on the character of the income.

Applying the Three-Tier Stack

The $2,800 in Tier 3 must be split by income type. Of the original $5,500, the tax-free character follows the dollars into the tiers proportionally, a nuanced computation IRS Form 8615 handles mechanically. For simplicity here, assume the Tier 3 dollars consist of roughly $1,100 in qualified dividends/long-term gains and $1,700 in ordinary income/short-term gains.

At the parent's rates: $1,100 × 15% (parent's long-term capital gains/qualified dividend rate) = $165. $1,700 × 24% (parent's ordinary marginal rate) = $408.

Total tax on the $5,500 of custodial account income: $0 (Tier 1) + $135 (Tier 2) + $165 + $408 (Tier 3) = $708.

Compare this to a world without the Kiddie Tax: if all $4,150 of taxable income were taxed at Adam's rate ($1,350 at 10% + $2,800 at 12%), the bill would be roughly $471. The Kiddie Tax adds $237 to the family's total tax cost on this income.

Who Writes the Check (or Files the Form)?

Adam owes the $708. The tax is his liability, computed on Form 8615, attached to his own Form 1040. His parents sign the return because he is a minor, but the IRS records the liability against Adam's Social Security number.

Practically, the parents will almost certainly pay the tax, the money comes from the custodial account, which they control as fiduciaries, or they write a check to avoid draining the account. But the legal obligation is Adam's. If the tax goes unpaid, the IRS sends notices to Adam (care of his parents, who opened the account and manage his affairs).

If Adam's parents instead elected Form 8814, the $708 would appear as additional tax on their own Form 1040. The mechanics shift, one return instead of two, but the tax owed does not change, and the liability concept remains rooted in Adam's ownership of the income-generating assets.

Cela illustre bien les mécanismes complexes qui déterminent qui déclare les revenus sur un compte de garde et qui en est finalement redevable.

When the Parent's Liability Becomes Real: Filing Mechanics

Two distinct filing paths exist when a child's custodial account income exceeds the Kiddie Tax threshold. The choice between them does not change the tax owed, but it does change whose return carries the computation, and can produce collateral consequences for the parent that are easy to overlook.

Form 8615 is the default path: the child files their own Form 1040 with Form 8615 attached. The form computes the tax on Tier 3 income using the parent's taxable income and filing status as inputs. The child needs the parent's tax information to complete it, specifically, the parent's taxable income from line 15 of Form 1040 and the parent's filing status. The parent does not sign the child's return as a taxpayer; they sign as the child's representative.

Form 8814 is the elective alternative. A parent can report the child's interest, dividends, and capital gains distributions directly on their own Form 1040 if the child meets these conditions: under age 19 (or under 24 and a full-time student), total income under the annual threshold (estimated at $13,500 for 2026), and income consisting only of interest, dividends, and capital gains distributions (IRS, 2025). The election eliminates the need for a separate child return, but embeds the child's income into the parent's return, where it can trigger unexpected consequences.

The parent who elects Form 8814 is not assuming the child's tax liability. The underlying ownership of the assets and the income remains the child's. What changes is only the administrative vehicle for reporting it.

Form 8814 vs. Form 8615: Which Path Applies?

Form 8814 seems attractive, one return, no separate filing for the child, less paperwork. But the election has a hard constraint: it only works for interest, dividends, and capital gains distributions. If the custodial account realized capital gains from actual sales (as opposed to mutual fund distributions), Form 8814 is unavailable. The child must file their own return with Form 8615.

Form 8615 applies when the child has unearned income above the Kiddie Tax threshold and does not qualify for, or the parent chooses not to use, Form 8814. It is also the only path when the child has earned income alongside unearned income, or when unearned income exceeds the Form 8814 gross-income cap.

Both forms compute the same Kiddie Tax amount. The difference is entirely about where the number lands: on the child's 1040 or on the parent's. The decision to use Form 8814 is reversible year by year and is not binding on future tax years.

Age Cutoffs That Change Everything

The Kiddie Tax applies based on three age categories, defined in IRC Section 1(g)(2):

• Under age 18: always subject to the Kiddie Tax, regardless of earned income or support.
• Age 18: subject to the Kiddie Tax only if the child's earned income does not exceed half of their own support for the year. An 18-year-old with a summer job covering most of their expenses may escape the Kiddie Tax entirely.
• Age 19 through 23: subject to the Kiddie Tax only if the child is a full-time student (enrolled for at least five months of the year) and earned income does not exceed half of support.
• Age 24 and older: Kiddie Tax no longer applies under any circumstances.

Once the child exits the Kiddie Tax age window, all unearned income is taxed at the child's own rate. This often means a steep drop in the effective tax rate on custodial account income, especially for children who have aged out but have not yet entered high-earning careers.

The Common Mistake That Shifts Unexpected Liability to Parents

The most consequential tax mistake families make with custodial accounts happens when a parent elects Form 8814 without modeling the downstream effects on their own return. The child's income, once embedded in the parent's Form 1040, increases the parent's adjusted gross income (AGI). This can trigger a cascade of adverse tax consequences that Form 8615, with the child filing separately, avoids entirely.

The trap catches parents who reason: "The account is the child's, my tax situation can't be affected." That logic holds for legal liability but fails for filing mechanics. Form 8814 makes the child's income visible inside the parent's return, and the parent's tax computation reacts to it.

Why Choosing Form 8814 Can Backfire

Adding several thousand dollars of custodial account income to the parent's AGI can produce multiple negative effects beyond the direct tax on that income:

• Bracket creep: the additional income may push a portion of the parent's own income into a higher marginal bracket, increasing tax on wages and other ordinary income.
• Phaseouts: the child tax credit, the American Opportunity Tax Credit, the Lifetime Learning Credit, IRA deduction eligibility, and the student loan interest deduction all phase out based on modified AGI. A Form 8814 election can reduce or eliminate these benefits.
• Net investment income tax: for parents with AGI above $250,000 (married filing jointly), the 3.8% NIIT may apply to the child's investment income when reported via Form 8814.

The tax cost from these indirect effects can exceed the convenience of filing a single return. A family claiming $4,000 in education credits could lose a substantial portion of that credit because the Form 8814 election pushed AGI past the phaseout threshold.

The Hidden AMT and Phaseout Risk

Form 8814 also exposes the parent to an often-overlooked risk: alternative minimum tax (AMT). The AMT calculation uses a different income base and exemption structure from the regular tax. Adding the child's investment income to the parent's return increases the AMT income base without necessarily increasing the AMT exemption, potentially triggering or increasing AMT liability.

A second subtlety: the Form 8814 election adds an extra tax amount equal to 10% of the child's gross income above a base amount, designed to compensate for the loss of the child's standard deduction when income is shifted to the parent's return. In most cases where the Kiddie Tax already applies, this extra tax is minor. But it underscores that Form 8814 is not a tax-avoidance tool, it is a simplification election that may carry a net cost.

What Changes When the Child Turns 18 (or 24 for Full-Time Students)

The Kiddie Tax stops applying at age 24 at the latest, and often earlier for children who work. Once the child is no longer subject to IRC Section 1(g), the entire three-tier structure collapses. Every dollar of unearned income, regardless of amount, is taxed at the child's own marginal rate.

For a 24-year-old graduate student with little earned income, this means a custodial account generating $10,000 in dividends and capital gains might be taxed entirely in the 10% and 12% brackets, dramatically lower than the parent's 24% or 32% rate that applied the year before. The tax planning implication is straightforward: deferring sales that trigger capital gains until the child ages out of the Kiddie Tax can produce significant tax savings.

Two practical caveats. First, the custodian must transfer legal control of the account when the child reaches the state's age of termination, typically 18 or 21, depending on the state and whether the account is UGMA or UTMA. The tax treatment shift and the legal control shift are separate events and may occur in different years. Second, the child becomes responsible for filing their own returns without a parent's signature. A 21-year-old who has never filed a tax return may need guidance through the process, particularly if the custodial account holds multiple securities with varying cost bases.

Il est important de noter que d'autres types de revenus, comme ceux issus des prêts de cryptomonnaies, posent également des questions fiscales spécifiques sur la taxation des prêts cryptos.

For more detail on the age thresholds and how they interact with filing obligations, see the breakdown of custodial account tax rules and the Kiddie Tax thresholds.

Sources

• irs.gov
• irs.gov
• law.cornell.edu
• investopedia.com

This content is educational and should not be read as an investment recommendation. Speak with a licensed advisor for guidance tailored to your circumstances.