No, you do not need to attach Form 1099-INT to your tax return. The bank, brokerage, or other payer that issued the form already sent a copy to the IRS, so your job is to report the interest accurately on Form 1040, not to forward paperwork the agency already has.
Why the IRS Doesn’t Want Your Copy
Any financial institution that pays you $10 or more in interest during the year is required to file Form 1099-INT with the IRS and mail you a copy.1Internal Revenue Service. About Form 1099-INT, Interest Income The agency matches those payer copies against what you report on your return, so sending yours along adds nothing.
If you e-file, there’s no mechanism to attach the form anyway. The system transmits the data you enter on Form 1040 and its schedules, and that’s it.
Paper filers follow the same rule with one narrow exception. If Box 4 of your 1099-INT shows federal income tax withheld under the backup withholding rules, the 1040 instructions have you include that amount on Line 25b of your return as a tax payment.2Internal Revenue Service. 1040 (2025) Some paper filers attach the 1099-INT to document that credit, but even then it isn’t strictly required.
State returns are a different question. Some states ask paper filers to include copies of 1099 forms with the state return. Check your state’s instructions before you throw the form away.
How to Report the Interest on Form 1040
Even without an attachment, every dollar of interest income still has to appear on your return. Form 1040 has two dedicated lines: Line 2a for tax-exempt interest and Line 2b for taxable interest.3Internal Revenue Service. Form 1040, U.S. Individual Income Tax Return Whether you can enter those totals straight on the 1040 or need to break them out on Schedule B depends on how much you earned and whether any special situations apply.
When You Can Report Directly on Form 1040
If your total taxable interest for the year is $1,500 or less and none of the Schedule B triggers below apply, add up the Box 1 amounts from every 1099-INT you received and enter the total on Line 2b. Tax-exempt interest from Box 8 goes on Line 2a.
When Schedule B Is Required
Schedule B itemizes your interest and dividend sources. You have to file it if any of the following apply:4Internal Revenue Service. About Schedule B (Form 1040)
- Your total taxable interest exceeds $1,500. Each payer’s name and interest amount go in Part I.5Internal Revenue Service. 2025 Instructions for Schedule B (Form 1040)
- You received interest as a nominee for someone else.
- You have accrued bond interest or original issue discount that doesn’t match what the 1099 shows.
- You’re excluding Series EE or I savings bond interest issued after 1989 that was used for qualified education expenses.
- You had a financial interest in or signature authority over a foreign account during the year.
The Part I total flows to Line 2b of your Form 1040. Tax-exempt interest doesn’t go on Schedule B at all; report it directly on Line 2a.5Internal Revenue Service. 2025 Instructions for Schedule B (Form 1040)
If a 1099-INT Never Arrived
You owe tax on all interest earned during the year, form or no form. The $10 threshold is a reporting requirement for the payer, not a floor for you. A savings account that earned $6 won’t generate a 1099-INT, but the $6 still belongs on your return.1Internal Revenue Service. About Form 1099-INT, Interest Income
If you expected a form and it never arrived, call the institution and ask for a duplicate. Most can reissue one quickly or confirm the amount from year-end statements. If you still can’t get it, calculate the interest from your account statements and report that figure.
If a Form Arrives After You File
A 1099-INT sometimes shows up in March from a brokerage you forgot about, or a corrected form replaces the original with different numbers. If the new information changes your tax liability, file Form 1040-X to amend the return.6Internal Revenue Service. What to Do When a W-2 or Form 1099 Is Missing or Incorrect
You generally have three years from the date you filed the original return, or two years from the date you paid the tax, whichever is later, to file an amendment and claim any refund that results.7Internal Revenue Service. Time You Can Claim a Credit or Refund If the late form means you owe more tax, filing sooner limits the interest that keeps accruing on the balance.
What Happens If the Numbers Don’t Match
Because the IRS already holds the payer’s copy, its automated matching system compares what was reported against what you claimed. When the two don’t line up, you get a CP2000 notice describing the discrepancy and proposing additional tax.8Internal Revenue Service. Understanding Your CP2000 Series Notice
A CP2000 is a proposed adjustment, not an audit. You can agree, partially agree, or dispute it by the deadline on the notice. Ignore it and the IRS finalizes the change, sends a bill, and starts charging interest. The underpayment interest rate for individuals is 7% per year, compounded daily, as of the first quarter of 2026.9Internal Revenue Service. Interest Rates Remain the Same for the First Quarter of 2026
The IRS can also assess an accuracy-related penalty of 20% of the underpaid tax if the omission counts as negligence, and the agency specifically lists “not including income on your tax return that was shown in an information return” as an example.10Internal Revenue Service. Accuracy-Related Penalty The unreported interest from a forgotten savings account rarely produces a big tax bill on its own, but the penalty and interest layered on top can outweigh the underlying amount.
Keep the Form Even Though You Don’t Send It
Hold on to every 1099-INT with your filed return. The IRS expects you to keep records supporting income on your return until the statute of limitations for that year expires.11Internal Revenue Service. How Long Should I Keep Records?
- Three years from the filing date is the standard retention period.
- Six years if you omitted more than 25% of your gross income, since the IRS has that long to assess additional tax.
- Indefinitely if you didn’t file a return at all.
For most taxpayers, three years is the practical minimum. Keeping the 1099-INTs with your filed return and matching bank statements in a single folder, physical or digital, makes any later IRS inquiry easy to answer.