Form W-9 for minors and custodial accounts
A custodial account belongs to the child. The IRS table settles it in three words: for a custodial account of a minor, give the name and SSN of the minor. An adult fills in the form and signs it, but every identifying detail on it is the child’s.
You opened a UTMA account for a nine-year-old and the brokerage wants a W-9. Your instinct is to put your own name and number on it, because you are the adult, you opened it, and the statements come to your address. Resist the instinct. The account is the child’s property, the dividends are the child’s income, and the taxpayer identification number the brokerage has to report under is the child’s Social Security number. Your role is administrative.
The minor’s SSN, the custodian’s pen
- Who the taxpayer is
- The minor
- Line 1
- The child’s legal name, as the SSA has it
- Line 3a
- Individual/sole proprietor
- Part I
- The child’s Social Security number
- Extra instruction
- Circle the minor’s name and furnish the minor’s SSN
- Who completes and signs it
- The custodian, in that capacity
- Kiddie tax
- A separate question, decided on Form 8615 and not on this form
The minor is the taxpayer
Row 4 of the What Name and Number To Give the Requester table reads: custodial account of a minor, Uniform Gift to Minors Act, give the name and SSN of the minor. Footnote 2 adds the mechanical instruction: circle the minor’s name and furnish the minor’s SSN. The rule has no exceptions worth chasing.
The reason it lands that way is ownership. A gift into a custodial account is irrevocable. The assets belong to the minor from the moment they go in, the custodian holds legal title in a fiduciary capacity rather than a beneficial one, and income the account generates is the minor’s income for tax purposes. The custodian’s duty is to manage property that is not theirs. Put a custodian’s SSN in Part I and you have told the IRS that the income belongs to the custodian, which is wrong on the tax law and will put dividends on the wrong Form 1040.
It attaches the whole account’s reported income to the adult. The child’s return, if one is required, then reports income with no matching information return behind it, while the adult receives a 1099 for income they do not owe tax on. Untangling it means a corrected return from the payer and, if the mistake has run for years, several of them.
Filling in the form for a minor
Nothing about the form changes because the taxpayer is eight years old. It is an individual’s W-9, completed the ordinary way, with one small oddity in the address lines.
Who signs for a minor
Here the primary sources go quiet, and it is more honest to say so than to invent a rule. Form W-9 states that the person whose TIN is shown in Part I should sign. It says nothing about what happens when that person is a child who cannot enter a binding certification. The Instructions for the Requester do not address it either.
What happens in practice is straightforward and nobody objects to it: the custodian signs, and writes their capacity next to the signature. Something like “Jane Doe, custodian for John Doe, a minor” leaves no doubt about who signed and why they were entitled to. Brokerages, banks and transfer agents see this constantly and have a house convention for it, so the fastest route to a form they will accept is to ask what they want to see. If the requester uses a substitute form, it may already have a capacity field.
One point that reduces the anxiety here. The signature only carries legal weight where the payment type requires it, and a custodial brokerage account paying dividends and interest is precisely a case where it does: accounts of that kind opened after 1983 must be signed or backup withholding applies. So do not skip it. But an older teenager with a summer 1099-NEC is in the “other payments” category, where the form requires a correct TIN and no signature at all, even though most requesters will still ask for one. The five signature rules
If the child has no Social Security number yet
Most children get an SSN at birth, but not all, and a custodial account occasionally gets opened before anyone applies. The form’s answer is to write “Applied For” in the space for the TIN, sign and date it, and give it to the requester. Then actually apply, on Form SS-5 with the Social Security Administration.
The grace period that follows is narrower than people assume, and for once the narrowness works in a custodial account’s favor. Sixty days to obtain and supply a TIN applies to interest and dividend payments and certain payments with respect to readily tradable instruments. It does not apply to other types of payments. A UTMA brokerage account paying dividends generally sits inside the sixty-day window; a teenager’s freelance invoice does not, and backup withholding applies to those payments until the number arrives. Applying for a TIN
The kiddie tax is a different question
Parents raise this immediately, and the two subjects genuinely do not touch. Here is the plain-English separation.
The W-9 answers an identification question. Whose taxpayer identification number does this payer report under, so that the IRS can match a Form 1099 to a return? For a custodial account the answer is the minor, which means the 1099 arrives with the child’s SSN on it. That is all the W-9 decides.
The kiddie tax answers a rate question, and it arises later, on a return rather than on a form. Congress did not want families shifting investment income to children to have it taxed in a low bracket, so a child’s unearned income above a threshold is taxed at the parents’ rate instead of the child’s. The computation lives on Form 8615, Tax for Certain Children Who Have Unearned Income, and it turns on the amount of unearned income, the child’s age, whether the child is a student, and the parents’ own bracket. The threshold is indexed, so the current figure belongs to the year’s Form 8615 instructions rather than to a reference page.
Reporting under the child’s SSN does not create the kiddie tax and would not avoid it if you reported under yours. Nor does it decide whether the child has to file a return at all, which depends on the amounts. Fill in the W-9 correctly, then take the 1099 to whoever prepares the returns and let them work out where the income is taxed and at what rate.
- Earned income sits outside the kiddie tax computation, so a teenager’s pay for services is not caught by it.
- Unearned income means dividends, interest, capital gain distributions and similar investment income, which is what most custodial accounts produce.
- A child may need to file a return in their own right. That is a threshold question about amounts, decided on the year’s filing rules.
- Where the numbers are large enough for any of this to matter, the cost of an hour with a preparer is trivial against getting it wrong for several years running.
A minor who is actually working
The other reason a W-9 lands in a teenager’s lap has nothing to do with custodial accounts. A sixteen-year-old builds websites, edits video, referees youth soccer, streams, or sells prints, and a payer asks for a W-9 before releasing money. Age is irrelevant to that request. Anyone receiving reportable payments as a non-employee gets asked, and the form is completed exactly as an adult freelancer would complete it.
- The child’s name on Line 1 and the child’s SSN in Part I. A parent’s number has no place on it.
- Line 3a, first box: Individual/sole proprietor. An EIN is unnecessary, though a working minor may obtain one. SSN or EIN
- A parent can help complete and sign the form, on the same capacity reasoning as a custodian.
- Net earnings from self-employment of $400 or more bring a self-employment tax filing obligation, which surprises families who assume a small amount of teenage income is invisible.
- Keep the records. Deductible expenses reduce that net figure, and a young person with no filing habit tends to have none.
A teenager doing regular scheduled shifts under supervision looks like an employee, and an employer handing them a W-9 instead of a Form W-4 may be classifying them wrongly. The consequences fall mostly on the business, but the practical cost lands on the worker, who pays both halves of the payroll tax and gets no withholding. Worth raising before the first shift.
Custodial account means two different things on this form
A note to save a wrong answer on Line 4. The phrase “custodial account” appears twice in the Form W-9 universe with unrelated meanings.
| Where it appears | What it means | What to do |
|---|---|---|
| Row 4 of the name and number table | A UGMA or UTMA account holding a gift for a minor | Give the minor’s name and SSN. Line 4 stays blank |
| Exempt payee code 1 | A custodial account under section 403(b)(7) meeting the requirements of section 401(f)(2), alongside tax-exempt organizations and IRAs | Code 1 applies to that retirement arrangement. Exempt payee codes |
A child’s UTMA account is not an exempt payee. Entering code 1 on it is a false statement on a certification, and the penalty for a false certification with no reasonable basis is $500 under IRC 6682. Leave Line 4 empty. Penalties
When the child turns eighteen
Custodianship ends at the age of majority or termination age set by state law, and the account transfers to the young adult outright. From the payer’s side the reporting barely changes, since the SSN was the child’s all along. What does change is who signs.
The account is retitled into the former minor’s sole name
The custodian’s role is over and the institution will usually initiate the paperwork. The Line 1 name and Part I number are unaffected.
The institution asks for a fresh W-9
Not always, but commonly, because the certification on file was signed by someone who no longer has authority to give it. Does a W-9 expire?
The new adult signs it themselves
Same name, same SSN, no capacity line. This is often the first W-9 anyone signs on their own behalf, and it is worth reading Part II properly before doing so. What you are certifying
Frequently asked questions
Whose Social Security number goes on a W-9 for a custodial account?
The minor’s. Row 4 of the IRS table covers a custodial account of a minor under the Uniform Gift to Minors Act and gives the answer as the minor, with a footnote telling you to circle the minor’s name and furnish the minor’s SSN. The custodian’s own number does not belong in Part I.
Can a child sign a W-9?
In practice the custodian signs, describing their capacity next to the signature. Neither the form nor the requester instructions set out a procedure for minors, so the requester’s own convention governs, and a brokerage that opened the account will already have one. Ask them rather than guessing.
What does the custodian write on Line 1?
The child’s legal name, matching the Social Security record. The custodian is not the taxpayer here and does not belong on Line 1. Where the requester’s form has room, the account title including the custodian can go on Line 2 or in the account number field on Line 7.
Does a UTMA account work the same way as a UGMA account?
The IRS table names the Uniform Gift to Minors Act, which most states have replaced with the Uniform Transfers to Minors Act. The rule reads across without difficulty: the assets belong to the minor, the custodian administers them, and the minor is the taxpayer whose SSN is furnished.
Is the kiddie tax the reason my child’s SSN is on the form?
These are two separate questions that happen to involve the same child. The W-9 decides whose taxpayer identification number a payer reports under. The kiddie tax rules on Form 8615 decide the rate applied to a child’s unearned income once it passes a threshold. Answering the first tells you nothing about the second.
My teenager was paid on a 1099-NEC. Who fills out that W-9?
The teenager is the payee, so the form carries their name, their SSN and the first Line 3a box. A parent can help with the paperwork. Money earned for services is earned income, which the kiddie tax computation does not reach, and net self-employment earnings of $400 or more bring a filing obligation of their own.
General information, not tax advice. This page explains a federal tax form in plain English. It is not legal, tax, or accounting advice, and W9Form.org is not affiliated with the IRS. Verify everything against the official Form W-9 page on IRS.gov and speak to a licensed professional about your own situation. How we source and review these pages.