If you’re wondering how much interest you need to report on taxes, the answer is all of it. Every dollar of taxable interest belongs on your federal return, starting at the first cent, whether or not a tax form shows up in your mailbox. The $10 figure you may have heard about is the threshold that forces a bank to send you a Form 1099-INT. It is not the threshold that triggers your obligation to report.
The $10 Form Threshold Is Not Your Reporting Threshold
A bank, brokerage, or other payer must file a Form 1099-INT with the IRS and send you a copy whenever the interest it paid you during the year reaches $10 or more. That rule governs the payer’s paperwork, nothing else.
Your rule is different. You are required to report all interest income on your federal return regardless of the amount and regardless of whether you received a form. Earning $3 in a savings account and leaving it off because no 1099 arrived is technically underreporting your income. The IRS states this plainly: you must report all taxable and tax-exempt interest even if you don’t receive a Form 1099-INT or Form 1099-OID.
If a payer owed you a 1099-INT and you never got one, contact them and ask for it. If it still doesn’t come, you report the income anyway using your own records. The missing form is the payer’s problem to fix. The unreported income would be yours.
What Counts as Interest You Have to Report
Taxable interest is any payment you receive for letting someone else use your money. The familiar sources are savings accounts, money market accounts, and certificates of deposit at banks and credit unions. It also covers interest-bearing checking accounts, corporate bonds, and loans you’ve made to other people. If you financed the sale of a property and the buyer pays you interest on the note, that income is fully taxable too.
A few categories have quirks worth knowing:
- Interest on U.S. Treasury securities (T-bills, notes, and bonds) is taxable federally but exempt from state and local income tax.
- Interest the IRS pays you on a delayed refund is taxable. You’ll get a 1099-INT if it’s $10 or more, but the full amount belongs on your return in any case.
- Interest from municipal bonds issued by state and local governments is generally exempt from federal tax. Even so, it still has to appear on your return, on Form 1040, Line 2a. The IRS uses that figure to calculate how much of your Social Security benefits are taxable and to check the alternative minimum tax.
- If you hold a bond issued at a discount, the original issue discount accrues as interest each year and is taxable even though you haven’t received cash. It’s reported to you on Form 1099-OID.
The short version: if someone paid you to borrow your money, assume it’s taxable interest and report it, unless it’s municipal bond interest, in which case report it on the tax-exempt line.
Where It Goes on Your Return
Your total taxable interest goes on Form 1040, Line 2b. Tax-exempt interest goes on Line 2a. If your total taxable interest for the year is $1,500 or less and none of the special situations below apply, you enter the number on Line 2b and you’re done.
You have to file Schedule B (Interest and Ordinary Dividends) if any of these are true:
- Your taxable interest for the year exceeds $1,500.
- You received interest from a seller-financed mortgage where the buyer uses the property as a personal residence.
- You received interest as a nominee for someone else, meaning the 1099 came in your name but part or all of the interest actually belongs to another person.
Schedule B asks you to list each payer by name along with the amount received from each. The total then flows to Line 2b on your 1040. There is no dollar limit on what you have to report. The $1,500 figure only determines whether you need the extra schedule.
What Happens If You Leave Interest Off
Unreported interest rarely stays hidden, because the IRS runs an automated matching program. Payers file copies of every 1099 with the IRS, and computers compare those figures against what you reported. When the numbers don’t match, you’ll receive a CP2000 notice proposing changes to your return and a revised tax bill.
The CP2000 isn’t a final bill. It’s a proposal with a response deadline. If you agree, you pay the difference. If you disagree, you send documentation. Ignoring it leads to a formal assessment, more interest, and potentially steeper penalties.
The penalties themselves depend on how the IRS characterizes the omission. For ordinary negligence or carelessness, the accuracy-related penalty is 20% of the underpayment attributable to the error. If you left $500 of interest off your return and your marginal rate is 22%, the extra tax is $110 and the penalty tacks on another $22, plus interest running from the original due date. If the IRS determines the underreporting was fraudulent, the civil fraud penalty is 75% of the underpayment due to fraud, and the IRS does not need a criminal conviction to impose it.
The tax on a few dollars of unreported interest is trivial. The penalty and interest on top of ignoring it are not. Tracking every interest-bearing account you hold, including the ones too small to generate a 1099, is the cheap way to stay out of this process entirely.
Special Situations Worth Flagging
A few scenarios change the calculation and are worth knowing about if they apply to you.
Interest on a Joint Account or Received for Someone Else
If a 1099-INT reports interest in your name that actually belongs to someone else, common with joint accounts where only one holder’s SSN is on the form, you report the full amount on Schedule B, subtract the nominee portion, and label the subtraction “Nominee Distribution.” You then issue a 1099-INT to the actual owner so they can report their share.
Interest You Paid at Purchase on a Bond
If you bought a bond between interest payment dates, you paid the seller for interest that accrued before you owned it. When the next payment arrives, your 1099 will include that accrued amount. On Schedule B, list the full interest, then subtract the accrued portion you paid at purchase and label it “Accrued Interest.”
A Child’s Interest Income
Interest a child earns is reportable under the same rules. For 2026, the first $1,350 of a child’s unearned income is tax-free, the next $1,350 is taxed at the child’s rate, and anything above $2,700 is taxed at the parent’s rate. This applies to children under 19, or under 24 if they’re full-time students. The child files Form 8615 to calculate the tax, or in some cases a parent can elect to include a child’s interest and dividend income on their own return using Form 8814.
Savings Bonds Used for Education
Interest from Series EE and Series I savings bonds issued after 1989 can be partially or fully tax-free if you use the proceeds for qualified higher education expenses. You claim the exclusion on Form 8815 and report the excluded amount on Schedule B. The exclusion phases out at higher incomes. For the 2025 tax year, the phase-out starts at a modified AGI of $99,500 for single filers and $149,250 for joint filers, and disappears at $114,500 and $179,250 respectively. The bonds must have been purchased by someone at least 24 years old at issue, and the expenses must be for you, your spouse, or a dependent.
Foreign Interest
Interest earned in foreign bank accounts or from foreign bonds is taxable on your U.S. return the same way domestic interest is, and it goes on the same lines of Form 1040. Foreign accounts also trigger separate disclosure obligations with their own thresholds and penalties, including the FBAR (FinCEN Form 114) if your combined foreign account balances exceed $10,000 at any point in the year, and Form 8938 at higher asset levels. If a foreign country also taxed your interest, you can usually claim a foreign tax credit to avoid being taxed twice on the same income.
None of these special rules change the baseline answer. The reporting floor for interest income is zero. The question is only where on the return it goes.