1099-INT box guide
1099-INT Box 1: Interest income
Understand taxable bank and investment interest and where it enters the federal return.
Return destination
Where the amount goes
Form 1040 taxable interest and Schedule B when required
1099-INT
Return to the complete form guide and reconciliation worksheet.
Checks before filing
- Compare the amount with year-end bank and broker statements.
- Do not add Treasury interest from Box 3 to Box 1 a second time.
- Combine Forms 1099-INT from every payer before testing Schedule B requirements.
How Box 1 works
Box 1 aggregates the taxable interest a single payer paid you during the year — deposit accounts, CDs, corporate bonds, and similar interest-bearing arrangements. It does not include interest already broken out into Box 3 (savings bond and Treasury interest) or Box 8 (tax-exempt interest); those describe interest too, but they live in their own boxes with their own tax treatment. Some payers also fold in tax-credit amounts from clean renewable energy bonds, qualified zone academy bonds, and similar programs, which the instructions treat as paid to you on the bond's own credit-allowance dates rather than when a payment physically arrived.
Each Form 1099-INT covers one payer relationship, so a taxpayer with several bank accounts, a brokerage cash sweep, and a few CDs across different institutions receives a separate Box 1 figure from each one — Schedule B requires listing every payer and combining the totals yourself, since no single form gives a portfolio-wide number. When a broker issues one composite statement covering several sub-accounts, cross-check the composite's headline Box 1 total against the per-account or per-CUSIP detail pages further back in the same statement, since the two are supposed to tie out exactly. A joint account reported under only one owner's taxpayer ID may require the other owner to file a nominee return to claim their share, rather than simply splitting the number informally.
Interest credited to an account is taxable when credited, not when withdrawn — a CD that automatically renews, or a savings account balance you never touch, still produces Box 1 interest for the year it accrues. Watch for a Box 1 figure on a bond that also shows premium amortization in Box 11: if the payer already reported a net amount in Box 1 reflecting that offset, no further Schedule B subtraction is allowed for the same bond, and subtracting the premium again would understate income.
Worked example
A taxpayer has three accounts: a savings account paying $42 in interest, a CD paying $310, and a brokerage cash sweep paying $18, each reported on its own Form 1099-INT with nothing in Box 3 or Box 8. The taxpayer's total Box 1 interest for Schedule B purposes is $42 + $310 + $18 = $370, combined across all three payers before testing whether the Schedule B reporting requirement applies.
Related 1099-INT boxes
Box 2: Early withdrawal penalty
Trace an early withdrawal penalty from Form 1099-INT to the eligible Schedule 1 adjustment.
Box 3: U.S. savings bond and Treasury interest
Separate federally taxable Treasury interest that may receive different state income-tax treatment.
Box 4: Federal income tax withheld
Reconcile backup withholding from interest with the federal withholding claimed on Form 1040.
Box 8: Tax-exempt interest
Report federally tax-exempt interest without including it in ordinary federal taxable interest.
Frequently asked questions
What does Box 1 mean on 1099-INT?
Box 1 generally reports taxable interest that is not assigned to a more specific Form 1099-INT box. Combine it with taxable interest from other payers, but keep Treasury and tax-exempt interest separate.
Do I owe tax on interest that stayed in my account and I never withdrew?
Yes. Interest is taxable in the year it's credited to your account, whether or not you withdraw it — a CD that auto-renews or a savings account you never touch still produces Box 1 interest for that year.
I have several 1099-INT forms from different banks — do I add them all together?
Yes. Each payer issues its own Form 1099-INT, and Schedule B requires listing every payer and combining the Box 1 (and other) amounts across all of them; there is no single consolidated federal form unless a broker chooses to issue one composite statement.
My joint account's 1099-INT only shows my name and Social Security number, but my spouse or co-owner funded most of it — what do I do?
If the form doesn't reflect how the account is actually shared, the recipient shown on the form generally needs to file a nominee return to pass along the other owner's share, rather than dividing the number informally in your own worksheets.