Yes, but the account structure depends on the child's age and your relationship

A grandparent can open a bank account for a grandchild, but the mechanics change depending on whether the child is a minor or an adult. For minors, you will need to open a custodial account — a legal structure where you hold the account in trust until the child reaches the age of majority (usually 18 or 21, depending on your state and the account type). For adult grandchildren, you can straightforward help them open their own account, or in some cases add them as an authorized user on your existing account.

The bank does not care about your family relationship. What matters is whether you have legal authority over the account. For a minor grandchild, that authority comes from being the custodian or guardian, or from having written permission from the child's parent or legal guardian. Without one of those, the bank will not let you open an account in the child's name.

Key Takeaways

  • A custodial account in the child's name requires you to name a custodian (usually yourself) and is held in trust until the child reaches age 18 or 21.
  • You will need the child's Social Security number, birth certificate, and written permission from the child's parent or guardian to open a custodial account.
  • Once the child reaches the age of majority, the account automatically transfers to their control — you cannot prevent this or keep the money.
  • Some banks offer joint accounts where you and the grandchild are both owners, which gives you access now but may complicate the child's finances later.
  • If the grandchild is an adult, you can help them open their own account or add them to yours as an authorized user without any custodial paperwork.

Custodial accounts: the standard structure for minors

A custodial account is the legal way to hold money for a minor. You open it at a bank, credit union, or brokerage in the child's name, but you name yourself (or another adult) as the custodian. The account belongs to the child — the money is theirs — but you control it until they reach the age of majority.

The two main types are UGMA accounts (Uniform Gifts to Minors Act) and UTMA accounts (Uniform Transfers to Minors Act). UTMA is broader and available in most states; it covers not just money but also real estate, securities, and other property. UGMA is older and more limited. Most banks and brokerages now use UTMA. The age at which the child takes control is set by your state law — usually 18 for UGMA and 21 for UTMA, though some states let you choose within a range.

To open a custodial account, you will need the child's Social Security number, their birth certificate, and written permission from the child's parent or legal guardian. Some banks require the parent to be present in person; others accept a signed letter. Call the bank first to ask what they require — requirements vary by institution.

What documents you need and where to get them

The bank will ask for three things: proof of the child's identity, proof of the child's Social Security number, and proof that you have permission to open the account on their behalf.

For identity, a birth certificate is standard. For the Social Security number, bring the Social Security card itself, or a tax return or W-2 that shows it. If the child does not have a Social Security number yet, you can explore for one at your local Social Security office or online at ssa.gov — the process takes about two weeks.

For permission, you need a signed letter from the child's parent or legal guardian stating that they consent to you opening a custodial account. Some banks provide a template; others accept any written statement. The letter should include the child's full name, date of birth, and Social Security number. If the child has two legal parents, both should sign unless one has sole custody — ask the bank whether they require both signatures.

Bring your own ID as well. The bank will verify your identity before opening any account.

What happens when the child turns 18 or 21

When the child reaches the age of majority set by your state law, the custodial account automatically converts to an account in their name alone. You lose all control — you cannot withdraw money, you cannot see the balance, and you cannot prevent them from closing it. This is by law, not by bank policy, so no amount of negotiation with the bank will change it.

Some custodians try to avoid this by opening a joint account instead of a custodial account. That is a mistake. A joint account means you both own the money now, which creates tax and legal complications, and it does not give you any more control later — the child can still withdraw everything and close the account the moment they turn 18.

If you want to give money to a grandchild with conditions attached — for example, only for college, or only after they turn 25 — a custodial account will not do that. You would need a trust, which requires a lawyer and costs more to set up. For straightforward saving, a custodial account is the standard tool.

Joint accounts: faster to set up, but with complications

Some grandparents open a joint account instead of a custodial account because it is simpler — no paperwork about guardianship, no age-of-majority conversion. You and the grandchild are both owners from the start.

The problem is that a joint account is legally yours and theirs right now. If you die, the account goes to the grandchild automatically — it does not go through your will or your estate. If the grandchild is sued or gets into debt, creditors can go after the account. If the grandchild is a minor and you want to prevent them from withdrawing money, you cannot — the bank will let them do it once they are old enough to sign their own checks or use a debit card.

For a minor, a custodial account is clearer legally and cleaner to manage. A joint account makes sense only if the grandchild is already an adult and you want to give them access to your money while you are alive.

Adding an adult grandchild to your account

If the grandchild is 18 or older, you can add them to your existing account as an authorized user or joint owner. This is simpler than opening a new account — the bank just needs the grandchild's name, date of birth, and ID.

As an authorized user, they can use the account (withdraw money, make deposits) but they do not own it. If you die, the account does not automatically go to them. As a joint owner, they own it equally with you, and it passes to them automatically if you die. Ask the bank which option they offer and what the difference means for your specific account type.

This route is useful if you want to give a grandchild access to money without opening a separate account, or if you want to teach them how to manage money by letting them use your account under your supervision.

Opening an account in the grandchild's own name

If the grandchild is an adult, they can open their own account. You do not need to be involved at all — they just need their ID, Social Security number, and an initial deposit (usually $25 to $100, depending on the bank). You can help them choose a bank, go with them to the branch, or even give them the money to deposit, but the account is theirs alone.

Some grandparents worry that if they give money to an adult grandchild, they lose track of it or the grandchild spends it on something the grandparent did not intend. That is true — once the money is theirs, you have no say in how they use it. If you want to give money with conditions, you need a trust or a written agreement, not a bank account structure.

Frequently Asked Questions

Do I need the parent's permission to open a custodial account?

Yes. The parent or legal guardian must give written permission. Some banks require them to sign in person; others accept a signed letter. Call your bank first to ask what they need. If the child has two legal parents, check whether both must sign or just one.

What happens to the money if I die before the child turns 18?

The custodial account belongs to the child, not to you, so it does not go through your will. It stays in the child's name and the bank will work with the child's parent or guardian to manage it until the child reaches the age of majority. The parent cannot take the money out for themselves — it is still the child's.

Can I use a custodial account to pay for college?

Yes, you can withdraw money from a custodial account for any reason, including college tuition. However, money in a custodial account counts as the child's asset on the FAFSA (Free process for Federal Student Aid), which can reduce their may be able to access for financial aid. A 529 college savings plan may be better if reducing aid may be able to access is a concern.

Can the grandchild access the money before age 18?

No, not without your permission. As the custodian, you control withdrawals. You can take money out for the child's benefit (education, medical care, living expenses), but the child cannot access it themselves until they reach the age of majority.

What if the parent refuses to give permission?

You cannot open a custodial account without the parent's consent. Your options are to ask the parent why they object and address their concerns, to wait until the grandchild is an adult and open an account for them directly, or to give money to the parent and let them manage it for the child.