40: Individual Income Tax Return 2025 (2025)
Idaho · Idaho Tax Commission · Used for tax years 2025
Idaho Form 40 is the 2025 Individual Income Tax Return. It reports income, deductions, credits, taxes, withholding, and payments to calculate your tax due or refund. It can also be used to amend a return.
When it's due
The supplied text does not state a filing deadline for 2025 Form 40.
It does state that Form 24 for the 2025 Food Tax Credit is due April 15, 2026. You can use Form 24 if you or your spouse are age 65 or older, qualify for the credit, and are not required to file an Idaho income tax return.
What you'll need
Have your identifying information ready, including your tax identification number, your spouse’s information if filing jointly or separately, and each dependent’s name, SSN, and birthdate.
Include these documents as applicable:
- A complete copy of your federal return. You do not need this if you are not required to file an income tax return and are filing Form 40 only for a Food Tax Credit refund.
- Legible state copies of W-2s, 1099s, and other information forms showing Idaho withholding.
- Federal Schedule A if you claim itemized deductions.
- Form 39R for applicable additions, subtractions, and credits. For the credit for tax paid to another state, also include that state’s return. Use a separate Form 39R for each state.
- Forms 44, 75, or 49ER when required for the credits, fuels taxes or refunds, or tax recapture you report.
- Form ID K-1 copies for amounts paid or withheld by an entity, and the Idaho Reimbursement Incentive Certificate if claiming that credit.
- Scanned receipts for qualifying Idaho food purchases if claiming actual sales tax costs for the Food Tax Credit.
- Federal Form 8332 or a court order if you are a noncustodial parent claiming a dependent, as directed in the instructions.
- Federal Form W-7 if you applied for an ITIN but have not received it before filing.
How to file
Print or type your information, complete the applicable lines, and include the required attachments. Sign the return. Both spouses must sign a joint return, and a paid preparer must sign if used.
Mailing addresses
Return with payment:
Idaho State Tax Commission
PO Box 83784
Boise, ID 83707-3784
Return only:
Idaho State Tax Commission
PO Box 56
Boise, ID 83756-0056
Make a check or money order payable to the Idaho State Tax Commission, write your SSN on it, and include it with your return. Do not staple it to the return or include a check stub. Do not send cash.
Electronic payment information is available at tax.idaho.gov/epay. ACH debit payments have no fee. The supplied text does not provide e-filing directions.
Forms and instructions are available at tax.idaho.gov/IITforms.
Common mistakes
- Missing signatures: Not signing delays processing. Both spouses must sign a joint return.
- Incorrect identification numbers: Make sure your return and W-2s show the correct SSN or ITIN. Errors delay refunds.
- Incorrect withholding claims: Do not claim federal withholding or withholding for another state as Idaho withholding. Do not include W-2s from other tax years or write on or change their amounts.
- Stapling documents: The form says not to staple. Do not staple your check to the return.
- Claiming the Food Tax Credit as a dependent: If someone else can claim you as a dependent, check line 12c and enter zero on line 43.
- Incorrect direct deposit information: Confirm your routing and account numbers with your bank. Choose checking or savings, not both, and do not include hyphens, spaces, or special symbols in the account number.
- Including the original return with an amendment: Complete the entire form and schedules using corrected amounts, but do not attach your original return.
- Trying to reverse a donation: Donations on lines 33 through 40 cannot be changed once made. A donated Food Tax Credit cannot be changed on an amended return.
Questions people ask
Can I use Form 40 to amend my return?
Yes. Check the amended-return box at the top and enter the number for your reason: 1 for a federal audit, 2 for a net operating loss carryback, 3 for a federal amended return, or 4 for another reason. Complete the entire form and schedules with corrected amounts and include the supporting documents required for your reason.
Can I file only to receive a Food Tax Credit refund?
Yes. If you are not required to file an income tax return, the instructions provide a special Form 40 procedure. It includes writing “NRF” on line 7, crossing through the $10 on line 31 and writing “NRF,” and entering your calculated Food Tax Credit on line 43. Follow the full refund-only steps on page 7. You do not need to include a federal return copy.
Do I have to use the same deduction method as on my federal return?
You can generally use federal itemized deductions or the standard deduction, whichever benefits you more. Idaho requires you to subtract state and local income taxes or general sales taxes from your federal itemized deduction amount. Some filers must itemize, including married-filing-separately filers whose spouses itemize.
Can I receive my refund by direct deposit?
Yes. Complete line 57 to deposit your refund into a bank account or an Idaho 529 College Savings (IDeal) account. If the financial institution rejects the deposit, you will receive a check by mail.
Can I apply my overpayment to next year instead of receiving a refund?
Yes. On an original 2025 return, you can apply all or part of your line 55 overpayment to your 2026 estimated tax. The amount applied will not be refunded to you.