Custodial Accounts (UTMA/UGMA): How They Work and What Nobody Tells You About the Kiddie Tax

If you want to invest for a kid but you've already maxed out (or don't want) a 529 plan, a custodial account is probably the next thing on your list. It's flexible, it's easy to open at almost any brokerage, and there's no annual contribution limit. But it comes with two catches most people don't find out about until later: the money legally belongs to the child the moment you put it in, and the IRS taxes the account differently than a normal brokerage account.

What a Custodial Account Actually Is

A custodial account is a regular investment or savings account opened by an adult on behalf of a minor. You, as the custodian, control the investments until the child reaches a set age. At that point, the account and everything in it transfers to them, no strings attached.

The two types are UTMA (Uniform Transfers to Minors Act) and UGMA (Uniform Gifts to Minors Act). An UTMA and UGMA account allow an adult, or a designated custodian, to manage the assets on behalf of a child until they reach the age of majority . The practical difference is what they can hold: UGMA allows parents or other adults to give cash and financial securities such as stocks and bonds to minors, while UTMA broadened the range of assets that could be transferred, including real estate and other property . Most states have moved to UTMA. In fact, as of 2026, only South Carolina and Vermont still have UGMA accounts .

UTMA vs. UGMA: The Age Issue

This is the part that trips people up. The age of majority for UGMA and UTMA accounts is typically 18 or 21 and depends on the state in which you live . Some states let the custodian set a later age when the account is opened, sometimes up to 25.

Whatever the age is in your state, once it hits, control shifts entirely. There's no way to say "actually, I want you to wait until you're more responsible with money." A common mistake is assuming you can restrict the funds like a trust — you can't. Once your child reaches that age, they can withdraw everything and spend it on a car, a trip, or nothing productive at all.

The Kiddie Tax: Where the Real Planning Happens

Custodial accounts are taxed in the child's name, which sounds great until you realize the IRS built a specific rule to stop parents from using this as a tax dodge. It's called the kiddie tax, and it applies to unearned income — interest, dividends, and capital gains — not wages from a summer job.

For 2025 and 2026, the brackets work like this: the first $1,350 of your child's unearned income will generally be tax-free, the next $1,350 will be taxed at your child's own federal income tax rate, and any unearned income above $2,700 will generally be subject to the kiddie tax and taxed at your marginal federal income tax rate .

In other words, a modestly sized custodial account that pays out dividends can quietly push a chunk of the earnings onto your own tax return at your rate — not the child's. Even custodial accounts holding investments that generate dividends or capital gains distributions can trigger the kiddie tax when no trading occurs .

There's a filing shortcut some parents use instead of filing a separate return for the child. If the child's gross income is less than $13,500 in 2026 or 2025, parents may elect to include the child's unearned income on their own tax return using IRS Form 8814 . It's simpler paperwork, but it doesn't lower the tax bill — it just changes who files.

Custodial Account vs. 529 Plan

These aren't competing for the same job, even though people often compare them.

Feature	Custodial Account (UTMA/UGMA)	529 Plan
Contribution limit	No annual contribution limits apply	State-specific lifetime limits, high but capped
What it can buy	Anything that benefits the child	Qualified education expenses only
Who controls it at maturity	The child, fully, at the age of majority	The account owner (usually parent) keeps control
Tax treatment	Subject to kiddie tax rules	Tax-free growth for qualified education use
Financial aid impact	Counted as the student's asset	Counted as the parent's asset (more favorable)

That last row matters more than people expect. UTMA and UGMA accounts are assessed more heavily in financial aid calculations because they're considered the child's assets, potentially reducing eligibility for need-based aid significantly compared to 529 plans . If college aid is part of your plan, a 529 usually does less damage to an aid package than a large custodial account.

Who a Custodial Account Actually Makes Sense For

• You want to invest for a child but have goals beyond just education — a first car, a business, a house down payment.
• You've already funded a 529 and want additional flexibility.
• You're comfortable with the fact that the child gets full, unrestricted control at 18 or 21.
• You're prepared to track and file for the kiddie tax if the account grows enough to generate meaningful dividends or gains.

If your main goal is strictly college costs and you want to keep the money out of the child's direct control until it's actually spent on tuition, a 529 plan is almost always the better tool. A custodial account is for broader, more flexible giving — with fewer restrictions and fewer tax perks.

The Bottom Line

A custodial account isn't complicated to open, but it's a legally binding gift the moment you fund it. Know your state's age of majority before you put in a large sum, plan around the kiddie tax thresholds if the account holds dividend-paying investments, and be honest with yourself about whether you actually want an 18-year-old to have unrestricted access to whatever balance builds up. If you're trying to figure out how a move like this fits into your bigger financial picture, running a quick check of your financial grade on Grade My Finance can help you see whether a custodial account, a 529, or just boosting your own retirement savings is the better next step.