Search Category: Income Tax
Business Income Tax Guides
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Business Income Tax Recordkeeping
Keep copies of your tax returns and all supporting documentation for a minimum of seven years. Visit the IRS website for more information on record keeping.
Businesses exercising the option to carry back or carry forward need to keep records for all affected years.
Business Income Tax: Laws and Rules
Laws and rules
Learn more about the laws and rules for Idaho business income tax:
- Idaho Code Title 63, Chapter 30 – Income Tax
- Idaho Code Title 30 – Corporations
- Idaho Code Title 53 – Partnership
- Idaho Code Title 68 – Trusts and Fiduciaries
- Income Tax Rules
- Income Tax Rules Committee
- 2022 Income Tax Rules Examples
Individual Income Tax Basics
This section covers Idaho individual income tax rates, residency, and filing requirements.
Income tax rate
The income tax rate for 2025 is 5.3% on Idaho taxable income.
Who needs to file
Residency status for filing
You must file individual income tax returns with Idaho if you’re any of the following:- An Idaho resident
- A part-year Idaho resident with income from Idaho sources or income earned while an Idaho resident
- A nonresident of Idaho with income from Idaho sources
| You’re a: | If you: | Tax Effect |
|---|---|---|
| Resident | Do either of these:
| Idaho taxes all your income, including income from sources outside Idaho. You might be entitled to a credit for taxes paid to another state if that state also taxes some or all the income that Idaho taxes. |
| Part-year resident | Do either of these:
| Idaho taxes:
|
| Nonresident |
| Idaho taxes only your income from Idaho sources. |
For more information about residency, also see:
Income requirement for filing
Idaho requires you to file if your gross income is above a certain amount. The amount varies depending on your residency status and possibly your filing status.
Gross income means all income from all sources before applying expenses or deductions. This income includes wages, interest, rents, dividends, gains from property sales, and gross business income.
If Idaho requires you to file an Idaho return, you must report Idaho Source Income. Also see the instructions for the Idaho return you need to file (more below).
Idaho residents
Idaho residents must file if their gross income for 2025 meets the requirements in the following table.
| Age as of the last day of 2025: | Gross income for 2025 is at least: |
|---|---|
| Single – under age 65 | $15,750 |
| Single – age 65 or older | $17,750 |
| Married (filing separately) – any age | $5 |
| Married (filing jointly) – both under age 65 | $31,500 |
| Married (filing jointly) – one age 65 or older | $33,100 |
| Married (filing jointly) – both age 65 or older | $34,700 |
| Head of household – under age 65 | $23,625 |
| Head of household – age 65 or older | $25,625 |
| Qualifying surviving spouse – under age 65 | $31,500 |
| Qualifying surviving spouse – age 65 or older | $33,100 |
Form 40 is the Idaho income tax return for Idaho residents. Instructions are in a separate file.
Part-year Idaho residents
Part-year Idaho residents must file if their total gross income is more than $2,500 combined from the following sources:
- All sources while an Idaho resident
- Idaho-source income while a nonresident
Form 43 is the Idaho income tax return for part-year Idaho residents. Instructions are in a separate file.
Nonresidents
Nonresidents of Idaho must file if their total gross income from Idaho sources is more than $2,500.
See Specific Circumstances of Residency and Idaho Source Income for detailed examples.
Form 43 is the Idaho income tax return for nonresidents with income from Idaho sources. Instructions are in a separate file.
Recordkeeping
Keep copies of your tax returns and all supporting documentation for at least seven years.
Laws and rules
Individual income tax
- Idaho Code Title 63, Chapter 30 – Income Tax
- Income Tax Rules
- Income Tax Rules Committee
- 2022 Income Tax Rules Examples
Residency status
- Idaho Code section 63-3030, Persons required to make returns of income
- Idaho Code section 63-3013, Resident
- Idaho Code section 63-3013A, Part-year resident
- Idaho Code section 63-3014, Nonresident
- Income Tax Rule 31, Aliens
- Income Tax Rule 40, Part-year resident
- Income Tax Rule 45, Nonresident
Idaho source income
- Idaho Code section 63-3026A, Computing Idaho Taxable Income of Part-year or Nonresident Individuals, Trusts, and Estates
- Idaho Code section 63-3013A, Part-Year Resident
- Income Tax Rules, 045, and 260 through 275
Decisions
Learn more about Idaho tax statutesAlso see these related topics:
Individual Income Tax Refund
Track refund progress 24/7
Use the refund status tool to get the most up-to-date information. The refund status graphic tracks a return’s progress through four stages.
You must file a return within three years of its original due date (often April 15), or any refund you’re owed for that return will expire. You should still file your tax return if it’s past the three-year limit, but we won’t be able to issue any refund.
Refunds for 2025 returns
Your refund for a 2025 Idaho income tax return could be different than what your return showed due to the conformity bill, which didn’t become law until after tax season started.
One change was an increase to the standard deduction. For anyone who filed using the smaller deduction (probably before mid-March), we’ll automatically use the new, larger amount to process your return. You don’t have to file an amended return.
- If you filed using the smaller standard deduction and already received a refund, we’ll send a second one. You’ll get it by direct deposit or check, depending on how you got the first one.
- If you filed using the smaller standard deduction and had to pay, you’ll receive any refund due. You’ll get it by check.
There are other conformity related deductions, such as the enhanced senior deduction, and those for car loan interest, tips from wages, and overtime compensation. You’d need to file an amended return if you filed before those deductions were implemented and wanted to take them.
When will 2025 refunds come?
- If you filed before March 10, 2026, you can expect your refund by the end of May.
- If you filed on March 10 or after, you should get your refund in the normal timeframe of 7 to 11 weeks.
Most people can check for their refund status at tax.idaho.gov/refund. If you already got a refund and are looking for the second, enter the amount of your first one.
If you had to pay when you filed using the smaller standard deduction, you can call 208-334-7660 or 800-972-7660 to get the new refund amount, assuming we’ve processed it. Or, wait for the refund to come in the mail.
Respond rapidly for faster refund
All income tax returns go through fraud detection reviews and accuracy checks before we issue any refunds. We might send you letters asking for more information.
- Fraud Detection: The Tax Commission uses a variety of methods to validate your identity and tax return to detect and combat tax identity theft. To help protect taxpayer information and keep taxpayer dollars from going to criminals, we might send you:
- An Identity Verification letter that asks you to take a short online quiz, provide copies of documents to verify your identity, or state that you didn’t file a return.
- A PIN letter that asks you to verify online whether you or someone you authorized filed the tax return we received.
- An Identity Verification letter that asks you to take a short online quiz, provide copies of documents to verify your identity, or state that you didn’t file a return.
- Accuracy Checks: We review all individual income tax returns each year for math errors or other errors. We find errors on about 25 percent of the returns. To be sure that your tax return correctly reflects your information and intent we might send you:
- A Request for Information letter that asks for missing or extra information to support data reported on the tax return.
- A Tax Computation Change letter that provides an explanation of changes that were made to the return.
- A Request for Information letter that asks for missing or extra information to support data reported on the tax return.
Speed up returns
- Review the return for accuracy before sending it.
- Verify that the correct address is on the return.
- Check for the correct Social Security numbers.
- Make sure W-2 information is correct when e-filing.
- Provide a driver’s license number when e-filing.
- Verify banking information when using direct deposit.
Understand typical refund time frames
- E-filers: You can expect your refund about seven to eight weeks after you receive an acknowledgment that we have your return.
- Paper filers: You can expect your refund about 10 to 11 weeks after we receive your return. We must manually enter information from paper returns into our database.
Exceptions
- First-time filers: It takes about three weeks to enter new filers into our system. Until that time, we’ll report your return as “not entered in system.” Add those three weeks to the estimates above to determine your refund timeline.
- If you received a letter from us asking for more information: Your refund will be delayed until we get the requested information. It will then take about six more weeks to finish the process.
More information
- If the Idaho Refund Status tool says your refund was mailed to you some time ago but you haven’t received it, contact Taxpayer Services for information on requesting a reissue of the check.
- If you think you may have been a victim of identity theft, check the resources on our Identity Theft page.
- Your refund could be seized to pay a debt with the IRS or another state agency.
- If you need help to prepare your tax return, check out the resources on the IRS website at Free Tax Return Preparation for Qualifying Taxpayers.
Individual Income Tax Update W-4
Make sure you have the right amount of income taxes withheld from your paycheck. Update your W-4 at least once a year or to account for changes in your life.
Forms and publications
- Form ID W-4 – Employee’s Withholding Allowance Certificate
- Itemized Deduction Worksheet for Idaho
- IRS withholding estimator
- Federal Form W-4
Retired? Scroll down for info on retirement and other sources of nonwage income.
Steps to take now
- Use the withholding estimator at IRS.gov to estimate your federal withholding. Update the federal Form W-4 with that information.
- Use page 2 of the Form ID W-4 – Employee’s Withholding Allowance Certificate to estimate your Idaho withholding. Fill out Form ID W-4 with that information.
- Give both W-4 forms to your employer.
If you owe money with your state tax return
- If you pay your income taxes by the April due date, penalty and interest don’t apply. You can make prepayments using our free Quick Pay service.
- If you can’t pay your taxes by the due date, penalty and interest apply. You can request a payment plan to spread out your payments.
Employers
- Please post this W-4 flyer for your employees at your workplace: Save Yourself from an Unexpected Tax Bill – Act NOW!
- Review the Withholding guide, for current information.
Guidance for retirement and other sources of nonwage income
If you’re receiving retirement or other sources of nonwage income:
- Determine if the income is taxable in Idaho.
- See the Idaho Income Tax Instructions for guidance.
- Taxable income can be:
- Retirement income
- Interest
- Dividends
- Generally, Idaho doesn’t tax Social Security income.
- If the income is taxable, follow the next steps.
Note: The entity paying the nonwage income might not withhold Idaho tax. It’s your responsibility to estimate the tax you’ll owe and be prepared to pay it.
If the entity paying the nonwage income will withhold Idaho tax for you:
- Use Form ID W-4 – Employee’s Withholding Allowance Certificate to determine:
- Your Idaho withholding status
- Your number of Idaho allowances
- Any additional amount to withhold
- See Form ID W-4 instructions.
- Consider each source of taxable income as a “job.”
- Use the information to complete a W-4, or use the entity’s W-4 substitute.
If the entity paying the nonwage income won’t withhold Idaho tax for you:
- Estimate your income tax for the nonwage income source.
- Estimate your annual income for the source.
- Estimate your tax on the income. Use the income tax rate schedule to estimate the total tax you’ll owe.
- Pay the tax you owe.
- Make estimated payments directly to the Tax Commission in one of these ways.
- Use Quick Pay (no log-in needed).
- Use Form 51 – Estimated Payment of Individual Income Tax.
- Pay the tax on or before April 15.
- Make estimated payments directly to the Tax Commission in one of these ways.
Current Individual Income Tax Forms
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Individual Income Tax Guides
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Extensions
Individuals, corporations, pass-through entities, and fiduciaries can file income tax returns up to six months from the original due date with a valid extension.
A valid extension means you can avoid a penalty for filing late. There aren’t any extensions allowing you to pay late. You’ll owe interest on any tax not paid by the original due date.
Even with a valid extension, you could owe penalties. Some common situations when penalties apply are if:
- You file on or after the original due date and pay tax due after you file.
- You file after the extended due date.
- You pay after the extended due date.
See the bottom of this page and the Income Tax Interest and Penalties page for more information.
Ensuring you have a valid extension
To avoid the late filing penalty, your prepayments (e.g., withholding, estimated payments or payments applied from previous refunds) must equal either:
- 80% of the estimated tax due for your current return
- 100% of the income tax reported on your return for the previous year
Keep in mind:
- If you didn’t file the previous year, you must pay 80% of the current year’s liability.
- If you filed a return the previous year and the “tax due” (immediately following the “Payments and Other Credits” section) was zero, you don’t need to make a payment to get the extension.
- If the necessary payment would be $50 or less, you don’t have to pay it to get the extension.
We have two worksheets to help you make sure you have a valid extension to file late:
After you finish the worksheet, do one of the following:
- If you need to make a payment, you can use our free, secure QuickPay service online to authorize a payment from your bank account. Or, mail the form at the bottom of the worksheet with your check.
- If you don’t need to make a payment, you don’t have to send us Form 51 or Form 41ES.
If you qualify for a valid extension, be sure to file your income tax return and pay any tax due by the extended due date. File and pay at the same time to avoid a penalty.
If you don’t have a valid extension
If it’s after the original due date and you don’t have a valid extension:
- File your income tax return as soon as possible.
- Pay as much as you can now. (Pay the entire amount due, if possible.) See the E‑Pay page for options.
These steps can greatly reduce the amount of interest and penalties you owe.
More about interest and penalty
You’ll owe interest and possibly penalties on all overdue tax payments. Idaho law requires us to charge interest.
In addition to the penalties mentioned above, other penalties can apply even if you have a valid extension. Penalties can vary from 0.5% per month to a maximum of 50% of the tax due. See the Interest and Penalties page for the different kinds of penalties and how we calculate them.
Forgot to File?
If you forgot to file your income tax returns or register for appropriate permits, this page will help you determine what to do next. Whether you’re an individual or a business, contact us so we can help you meet any filing requirements you might have overlooked.
We don’t capture any personal data when you visit this site; it’s strictly for your information. Learn more about how the Tax Commission protects your privacy.
Should you contact us?
Please get in touch with us if any of the following situations apply:
You…
- Haven’t filed income tax returns for one or more years.
- Haven’t filed because you don’t have the money to pay the tax due.
- Live in Idaho but work in another state and haven’t filed.
- Live in another state but work in Idaho and haven’t filed.
- Conduct business in Idaho and haven’t filed.
- Have employees and need a withholding permit.
- Make sales in Idaho and need a seller’s permit.
- Are unsure about whether you have to file returns.
Penalties
Although we can’t waive interest, we’ll consider reducing any penalties that apply if you file your return voluntarily. Visit our Penalties and Interest page for more information.
Need help or have questions?
Please email us at Forgot_to_File@tax.idaho.gov or at one of the numbers below.
| Contact Information | |
|---|---|
| For individual tax returns | (208) 332‑6641 [Boise] (800) 972‑7660, ext. 6641 [toll‑free] |
| For business tax returns | (208) 954-8861 [Boise] (800) 972‑7660, ext. 8861 [toll‑free] |
| For information about recent delinquencies, please contact our Taxpayer Services office | (208) 334‑7660 [Boise] (800) 972‑7660 [toll‑free] |