Yes, you pay tax on interest from a joint savings account, but only on the portion you actually own
The IRS taxes interest income wherever it comes from. If your joint account earns interest, that interest is taxable to whoever owns the money in it. If you and another person each own half, you each report half the interest on your own tax return. If you own 70% and someone else owns 30%, you report 70% of the interest. The bank will send a 1099-INT form showing the total interest earned, but you are responsible for reporting only your share.
The tricky part is proving what you actually own. The IRS does not automatically know. If you cannot show documentation of who contributed what, the IRS may assume you each own 50%, even if that is not true. This matters most when one person puts in all the money but the account is titled in both names, or when contributions are unequal.
Key Takeaways
- Interest from a joint account is taxable income, and you report only the percentage you own, not the full amount the bank reports.
- The bank sends a 1099-INT to the Social Security number listed first on the account, so the primary account holder may need to split the reported interest with the co-owner.
- If you cannot prove your actual ownership share with bank records or a written agreement, the IRS may assume 50/50 ownership regardless of who contributed the money.
- Spouses filing jointly report joint account interest together on one return, but unmarried co-owners must each report their own share on separate returns.
- You should keep records of deposits, withdrawals, and any agreement about who owns what portion of the account.
How the 1099-INT works with joint accounts
Banks report all interest earned on a joint account on a single 1099-INT form. That form goes to the Social Security number of the person listed first on the account. If you are the second person listed, you will not receive a 1099-INT directly from the bank—the first person will get it.
This creates a reporting problem if you own part of the account but are not the primary account holder. The IRS will see the full interest amount reported under the first person's name. If that person reports the full amount on their tax return and you report nothing, the IRS has a record of income that does not match the return. You need to report your share even though the 1099-INT went to someone else.
The person who receives the 1099-INT should either report only their share and give you documentation of your share, or you should contact the bank and ask them to issue a corrected 1099-INT splitting the interest between both owners. Not all banks will do this, so the first option—keeping your own records and reporting your share—is more reliable.
Proving your ownership share to the IRS
The IRS does not require you to file anything special to claim your ownership share, but you must be able to prove it if audited. The strongest proof is a written agreement between you and the co-owner stating what percentage each person owns. This agreement should be dated and signed by both parties.
If no written agreement exists, bank records showing deposits from each person can help. If you deposited $5,000 and the co-owner deposited $5,000, and no other deposits were made, you have evidence of 50/50 ownership. Withdrawals complicate this—if one person withdrew money, it is less clear who that money belonged to. Keep statements showing the account balance and all transactions.
Without documentation, the IRS typically assumes joint tenants own equal shares. So if you own 80% but have no proof, you may be taxed as if you own 50%. This works against you if you own more than half, and in your favor if you own less than half.
Married couples filing jointly
If you are married and file a joint tax return, the distinction between your share and your spouse's share does not matter for federal income tax. You report all interest from all joint accounts on one return together. The 1099-INT goes to one person's Social Security number, but both spouses are responsible for the tax on the full amount.
This simplifies things: you do not need to split the interest or prove ownership percentages. You just add the total interest to your joint return. State taxes may differ—some states tax married couples separately even if they file jointly federally—so check your state's rules.
Unmarried co-owners and separate tax returns
If you are not married to the co-owner, each of you files your own tax return and reports only your share of the interest. This is where documentation becomes critical. If the bank reports $500 in interest and you own 40%, you report $200 on your return. The other person reports $300.
The problem arises when the 1099-INT shows $500 under the first person's name. The IRS sees that $500 reported under one person's Social Security number. If the first person reports $500 and you report $200, the IRS sees $700 in reported interest from a $500 account, which triggers a mismatch. If the first person reports $250 and you report $250, the IRS sees $500 total, which matches—but only if you both coordinate your reporting.
The safest approach is to ask the bank to split the 1099-INT before tax season. If they will not, the person who receives the 1099-INT should report only their share and provide you with a written statement of how much interest belongs to you. You then report your share and keep that statement with your tax records in case of an audit.
What happens if you do not report your share
If you own part of a joint account but do not report the interest income, you are underreporting your income. The IRS matches 1099-INT forms to tax returns. If the bank reports $500 in interest and nobody reports it, or only part of it is reported, the IRS will notice.
The penalty for underreporting interest income is typically a failure-to-pay penalty plus interest on the unpaid tax, plus possible accuracy-related penalties if the underreporting is substantial. The IRS may contact you or the primary account holder asking for an explanation. It is easier to report your actual share from the start than to deal with a notice later.
If you genuinely did not know you were supposed to report it, you can amend your return using Form 1040-X and pay the back tax plus interest. The IRS is usually more lenient with people who correct the error themselves than with people who wait to be caught.
Minors and joint accounts with parents
If a parent opens a joint savings account for a minor child, the interest is still taxable. The parent does not automatically report it just because they are the parent. The interest belongs to whoever owns the account, based on who contributed the money.
If the parent opened the account with their own money and added the child's name for convenience, the parent owns the interest and reports it. If the parent deposited $1,000 and the child deposited $1,000 from a job or gift, they each own half and each reports half the interest on their own return (or the parent reports it on the child's return if the child is a dependent).
A child with earned income may be able to use the standard deduction to avoid owing tax on small amounts of interest, but the interest is still income and must be reported. Check the current year's standard deduction limits for dependents.
Frequently Asked Questions
Do I have to report interest if the account earned less than $10?
Yes. The IRS taxes all interest income, regardless of amount. Banks only issue a 1099-INT if interest is $10 or more, but you still owe tax on smaller amounts. You report it on your return even if you do not receive a form.
What if my co-owner and I disagree about who owns what percentage?
You each report based on what you believe you own and keep documentation to support it. If the IRS audits either of you, you will need to prove your claim. A written agreement signed by both parties before the audit is the strongest evidence. Without one, bank records of deposits and withdrawals are your next best option.
Can I avoid taxes by putting money in someone else's joint account?
No. If you own the money, you owe tax on the interest it earns, regardless of whose name is on the account. Putting your money in someone else's account does not change the tax treatment—it just creates confusion about who actually owns it.
Do I report the interest on my state tax return too?
Most states tax interest income the same way the federal government does. You report your share of the interest on your state return as well. A few states have no income tax, so check your state's rules. If you live in one state and the account is in another, you may owe tax in both states.
What if the bank refuses to split the 1099-INT?
Keep your own records showing your ownership share and report only that amount on your tax return. Include a note with your return explaining that the 1099-INT was issued to the co-owner but you are reporting your share. Keep bank statements and any written agreement proving your ownership in case the IRS asks questions.