Yes, you can open a savings account for your granddaughter, but the rules depend on her age and your relationship to the bank

If your granddaughter is under 18, you can open a custodial savings account (also called a minor's account or UTMA account) in her name with yourself as the custodian. You will be the legal owner and decision-maker until she reaches the age of majority—18 in most states, 21 in a few. The money in the account belongs to her, not to you, and you cannot use it for your own expenses.

If she is 18 or older, she can open her own account without you. However, many banks allow you to co-own an account with an adult granddaughter if you both want that arrangement. The rules for joint accounts are different from custodial accounts and come with different tax and legal consequences.

The specific steps and requirements vary by bank and by state. Some banks have minimum deposit amounts, age restrictions on who can be a custodian, or limits on how much you can deposit per year without tax reporting. Before you choose a bank, confirm what they offer for minors' accounts and what documents you will need to bring.

Key Takeaways

  • A custodial savings account lets you open an account in your granddaughter's name if she is under 18, with you as the custodian who controls the money until she reaches adulthood.
  • You will need her Social Security number, birth certificate or state ID, and proof of your relationship (birth certificate showing you as grandparent, or adoption papers) to open the account.
  • The money in a custodial account belongs to your granddaughter, not to you, and counts as her income for tax purposes if it earns interest above a certain threshold.
  • If your granddaughter is 18 or older, she can open her own account, or you can open a joint account together if the bank allows it.
  • Different banks have different rules about minimum deposits, fees, and whether they offer accounts for minors, so call ahead or check their website before you visit.

What documents you need to bring to open a custodial account

Bring your granddaughter's Social Security number and a form of ID showing her date of birth. A birth certificate works, or a state ID or passport if she has one. The bank will verify her identity and age before opening the account.

Bring proof that you are her grandparent. A birth certificate that lists both her parents and shows you as the parent of one of them is the clearest proof. If you are a step-grandparent or adopted grandparent, bring adoption papers or marriage certificates that show the relationship. Some banks will accept a combination of documents—for example, your granddaughter's birth certificate plus your ID plus a document showing you are the parent of her parent.

Bring your own ID and Social Security number. The bank needs to verify who you are and run a background check before you can be named as custodian. Some banks also ask for proof of address, such as a utility bill or lease.

Call the bank before you go. Ask whether they have a checklist of documents they need, whether they require an in-person visit or allow you to open the account online, and whether there is a minimum deposit amount. Some banks have different requirements for different types of accounts.

How custodial accounts work and what happens when she turns 18

Once the account is open, you can deposit money whenever you want. You control the account—you can withdraw money, move it between accounts at the same bank, and make decisions about how it is invested. Your granddaughter cannot withdraw money or make changes without your permission, even if she knows the account exists.

The money earns interest (or grows through investments, depending on the account type). That interest counts as your granddaughter's income for tax purposes, not yours. If the interest is above a certain amount each year, you may need to file a tax return for her or report it on your own return. The threshold changes each year; check the IRS website or ask your tax preparer what the current limit is.

When your granddaughter reaches the age of majority—18 in most states—the account automatically transfers to her full control. You no longer have the right to withdraw money or make decisions. Some banks require you to sign paperwork to transfer ownership; others do it automatically. Contact the bank a few months before her 18th birthday to ask what the process is.

Once she owns the account, she can withdraw all the money, close it, or leave it open. You have no say in what she does with it. If you want to ensure the money is used for a specific purpose (like college), a custodial account is not the right tool—you would need a trust or a 529 education savings plan instead.

Tax reporting for custodial accounts

Interest or investment earnings in a custodial account are taxed as your granddaughter's income. If the earnings are small (below the annual threshold, which varies by year), no tax return is needed. If they exceed the threshold, you must file a tax return for her, or report the income on your own return depending on the amount and your tax situation.

The bank will send you a 1099-INT form (for interest) or 1099-DIV form (for dividends) each January showing how much was earned. Keep this form for your tax records. If you are unsure whether you need to file a return for your granddaughter, ask a tax preparer or check the IRS website for the current income thresholds.

The money you deposit into the account is not taxed—only the earnings are. Deposits are considered gifts from you to your granddaughter. There are no federal gift taxes on small gifts, but if you give very large amounts (over the annual gift tax exclusion, which changes each year), you may need to file a gift tax return. Ask a tax preparer if you plan to deposit large sums.

Custodial accounts versus other ways to save for a minor

A custodial account is simple and flexible. You can deposit any amount, withdraw for any reason, and the money transfers to your granddaughter at 18. The downside is that the money becomes hers to use however she wants once she reaches adulthood—you cannot restrict how she spends it.

A 529 education savings plan is designed specifically for college or other education costs. Money grows tax-free if used for tuition, room and board, books, or other education expenses. If the money is used for something else, you pay taxes and a penalty on the earnings. A 529 gives you more control over how the money is used, but it is less flexible if your granddaughter does not go to college or if circumstances change.

A trust is more complex and expensive to set up, but it gives you the most control. You can specify exactly when and how your granddaughter receives the money—for example, at age 25 instead of 18, or only for education or medical expenses. A trust requires a lawyer to create and may require ongoing paperwork and tax filings. It is usually worth considering only if you are saving a large amount or have specific conditions in mind.

For most grandparents saving modest amounts with no special conditions, a custodial account is the most straightforward choice.

What happens if your granddaughter is 18 or older

If your granddaughter is already an adult, she can open her own savings account at any bank. She will need her ID and Social Security number. You do not need to be involved unless she asks you to be.

If you both want to own the account together, you can open a joint account. Both of you will have full access to the money and can withdraw or make changes without permission from the other. Joint accounts are simpler than custodial accounts because there is no age restriction or transfer process—you both own it equally from the start. The downside is that either of you can take all the money out, and the account does not automatically transfer to her when you pass away (it becomes part of your estate).

If you want to give her money but keep some control over how it is used, a joint account is not the right tool. You would need a trust or a written agreement, and you should talk to a lawyer about the best structure for your situation.

Frequently Asked Questions

Can I use the money in my granddaughter's custodial account to pay for her expenses?

Yes, you can withdraw money to pay for her reasonable living expenses—food, clothing, school supplies, medical care. However, you cannot use it for expenses you are already legally required to pay, such as child support. The money belongs to her, not to you, so using it for your own personal expenses is not allowed and could have legal consequences.

What if I want to change who controls the account after I open it?

You cannot transfer custodianship to someone else once the account is open. If you become unable to manage the account, contact the bank and ask what options are available—some banks allow you to name a successor custodian in advance. If you want someone else to take over, you may need to close the account and have that person open a new one, which can be complicated. Plan ahead if you think this might happen.

Does a custodial account affect financial aid for college?

Yes. Money in a custodial account counts as your granddaughter's asset when she applies for federal student aid (FAFSA). Assets in a student's name reduce the amount of aid they may receive. A 529 plan is treated differently and may have less impact on aid, depending on who owns it. If college aid is a concern, talk to a financial aid advisor before deciding which account type to use.

Can I open a custodial account online, or do I have to go to the bank in person?

Some banks allow you to open a custodial account online, but many require an in-person visit so they can verify your identity and your granddaughter's identity. Call the bank or check their website to find out. If you must visit in person, bring all required documents so you do not have to make a second trip.

What if my granddaughter's other grandparent wants to add money to the account?

They can make deposits as a gift, but they cannot be a co-custodian. Only one person can be the custodian. If both grandparents want equal control, you would need to open a joint account instead, but that only works if your granddaughter is 18 or older. If she is a minor, the other grandparent can give you money to deposit on her behalf, but you remain the sole custodian.