On a joint bank account, tax follows the money, not the name order. Whoever contributed the funds owes tax on the interest those funds earned, split in proportion to what each owner put in. The bank will report the whole amount under one owner’s Social Security Number, but that reporting choice does not decide who the IRS considers the taxpayer. For spouses filing jointly, the distinction rarely matters. For everyone else sharing an account, it matters a lot, and there is a specific process for fixing the record when the 1099 lands on the wrong person.
How the Bank Reports the Interest
When a joint account is opened, the bank ties one Social Security Number to it for tax reporting. That person becomes the primary holder in the bank’s system. Each January, the bank issues a Form 1099-INT for the total interest paid the prior year and files it with the IRS under that single tax ID.1Internal Revenue Service. Publication 550, Investment Income and Expenses The bank does not attempt to divide the income between owners or check who deposited what. The full amount posts to one person’s record.
If the account holds investments that pay dividends, a Form 1099-DIV comes instead of or in addition to the 1099-INT.2Internal Revenue Service. Instructions for Form 1099-DIV (01/2024) The same single-SSN logic applies. And if the account earned less than $10 in interest for the year, no 1099-INT is issued at all, but the income is still taxable and still has to be reported.3Internal Revenue Service. Instructions for Forms 1099-INT and 1099-OID (01/2024)
Splitting the Tax by Contribution
The IRS looks at beneficial ownership, which comes down to a simple question: who put the money in? Deposit 100% of the funds into a joint savings account and you owe tax on 100% of the interest, even if your co-owner has full legal authority to withdraw every dollar tomorrow.1Internal Revenue Service. Publication 550, Investment Income and Expenses
When both owners contribute, the tax burden splits by share. If you and a sibling each put $5,000 into a $10,000 CD, each of you reports 50% of the interest on your own return. Publication 550 states the general rule this way: each person’s share of interest or dividends from jointly held property is determined by local law, which in most states means proportional to contribution.1Internal Revenue Service. Publication 550, Investment Income and Expenses
Keep records of who deposited what. A spreadsheet is enough. Without one, and with a question raised during an audit, the IRS will default to taxing whoever’s SSN appears on the 1099.
When the Co-Owner Is Your Spouse
Most joint accounts are held by married couples, and for a joint return the question effectively disappears. All of the income lands on the same Form 1040 regardless of whose SSN the bank used.
Even when spouses file separate returns, the IRS provides a shortcut: you do not have to issue a nominee 1099-INT to your spouse.1Internal Revenue Service. Publication 550, Investment Income and Expenses You use Schedule B to subtract your spouse’s share from your reported interest, and your spouse reports their share on their own return. No separate 1099 has to be created and filed.
Community property states change this. Arizona, California, Idaho, Louisiana, Nevada, New Mexico, Texas, Washington, and Wisconsin follow community property rules, under which interest and dividends from community property are generally split 50/50 between spouses filing separately, regardless of who contributed or whose name is on the account.4Internal Revenue Service. Publication 555, Community Property Spouses filing separately in these states report the split on Form 8958.
The Nominee Distribution Process
If the 1099-INT includes income that belongs to someone other than your spouse, you have to run through the nominee distribution process. This is how the IRS lets you move reported income from the person whose SSN received the 1099 to the person who actually earned it. Skip it and you either pay tax on money that isn’t yours or trigger an IRS notice when the two returns fail to match.
On Schedule B of your Form 1040, list the full amount of interest shown on your 1099-INT. Below the subtotal, write “Nominee Distribution” and the amount that belongs to the other owner. Subtract it, and the remainder is your taxable interest.5Internal Revenue Service. 2025 Instructions for Schedule B (Form 1040) The same steps work on Part II of Schedule B if the 1099-DIV includes dividends belonging to someone else.
Then issue the other owner their own Form 1099-INT. List yourself as the payer and the other owner as the recipient. File a copy with the IRS along with Form 1096 as the transmittal cover sheet.6Internal Revenue Service. Form 1096, Annual Summary and Transmittal of U.S. Information Returns That creates the paper trail the IRS uses to match what you subtracted from your return to what the other owner reports on theirs.
Deadlines
Nominee 1099 deadlines run earlier than most people expect. For the 2026 tax year, the recipient’s copy is due by January 31, 2027. Paper filings with the IRS are due February 28, 2027; electronic filings get an extra month, until March 31, 2027.7Internal Revenue Service. Publication 1099, General Instructions for Certain Information Returns (2026) A due date landing on a weekend or holiday shifts to the next business day.
Accounts Shared With a Minor Child
When a child is added to an account or a custodial account is opened and the funds are the child’s, the income generally belongs to the child. The IRS then applies rules that keep parents from parking investment income under a child’s lower rate.
For 2026, a child’s unearned income above $2,700 is taxed at the parents’ marginal rate rather than the child’s. This kiddie tax applies to children under 18, children who are 18 and don’t earn more than half their own support, and full-time students aged 19 through 23 who don’t earn more than half their own support.8Internal Revenue Service. Topic No. 553, Tax on a Child’s Investment and Other Unearned Income The child reports it on Form 8615.
When the child’s total interest and dividend income for 2026 falls between $1,350 and $13,500, parents can elect to include it on their own return using Form 8814 instead of filing a separate return for the child.9Internal Revenue Service. Form 8814, Parents’ Election To Report Child’s Interest and Dividends The election is convenient but not always cheaper, because income above the base amount ends up taxed at the parent’s rate. Compare the two before choosing.
Gift Tax When a Co-Owner Withdraws
Adding money to a joint account is not itself a gift. The potential gift arises when the other owner withdraws funds they didn’t contribute. If you deposit $50,000 and your non-spouse co-owner takes $20,000 for their own use, the IRS may treat that withdrawal as a $20,000 gift from you.
The annual gift tax exclusion for 2026 is $19,000 per recipient.10Internal Revenue Service. What’s New — Estate and Gift Tax In that example only $1,000 exceeds the exclusion, which triggers a filing requirement on Form 709. Actual gift tax is unlikely to be owed unless your lifetime gifts exceed the combined estate and gift tax exemption, but the return still has to be filed. Transfers between spouses are generally unlimited and exempt, one more reason spousal accounts stay simple.
What Happens If You Skip the Fix
The common failure is the primary holder ignoring the nominee process. When the IRS gets a 1099-INT showing $2,000 in interest under your SSN and your return reports $1,000, automated matching flags the gap. A notice arrives proposing tax on the missing $1,000 plus interest. Without documentation that the income belonged to someone else, you pay it.
On top of matching notices, the IRS can impose a 20% accuracy-related penalty on any underpayment caused by negligence or a substantial understatement of income.11Office of the Law Revision Counsel. 26 USC 6662 – Imposition of Accuracy-Related Penalty on Underpayments Failing to issue nominee 1099-INT forms you were required to file carries its own per-form penalties, and those compound across tax years.
If you are the primary holder on a joint account with anyone other than your spouse, set a January reminder to prepare nominee forms as soon as your own 1099-INT arrives. Once a year it is a small task. Untangling a mismatch notice later is not.