Individual Income Tax

Idaho residents are taxed on their total income, including income earned in another state or country. Part-year residents are taxed on all income received while living in Idaho, plus any income received from Idaho sources while living outside of Idaho. Nonresidents are taxed only on income from Idaho sources.

Tax rate

The income tax rate ranges from 1.6 to 7.4 percent on Idaho taxable income. Individual income tax is graduated so higher earnings are taxed at a higher rate.

Forms/publications

• Form 24 (and more information on the Idaho Grocery Credit)
• Form 39R, Idaho Supplemental Schedule (for residents)
• Form 39NR, Idaho Supplemental Schedule (for nonresidents or part-year residents)
• Form 40, Idaho Individual Income Tax Return
• Form 40V, Income Tax Payment Voucher
• Form 43, Idaho Part-Year Resident & Nonresident Income Tax Return
• Form 51, Estimated Payment of Idaho Individual Income Tax
• Form CG, Idaho Capital Gains Deduction
• Form ID-MS1, the Employee's Idaho Military Spouse Withholding Exemption Certificate
• Instructions packet (including tax tables for individual income tax)
• Full list of current individual income tax tax forms and all required schedules »
• Idaho Medical Savings Account brochure
• Idaho Community Property brochure

Filing requirements

Individual income tax requirements are adjusted for inflation each year, and full filing information can be found in the Individual Income Tax instructions packet. For 2012, full-year residents must file if their gross income is at least:

Part-year residents must file an Idaho income tax return if their gross income from all sources while a resident and gross income from Idaho sources while a nonresident is more than $2,500.

Nonresidents must file an Idaho income tax return if their gross income from Idaho sources is more than $2,500. This includes special-case Idaho residents, who are domiciled in Idaho but are considered nonresidents for income tax purposes. Special-case Idaho residents don't have to file an Idaho income tax return if they're absent from the state for at least 445 days in a 15-month period. However, they must meet certain qualifications, which are listed on page 2 of our publication, Residency Status and Idaho Source Income.

Gross Income means all income from all sources before applying expenses or deductions. This includes compensation for services, gross income of a business, interest, rents, dividends, and gains from the sale of property. It also includes a partner's or shareholder's share of the gross income of a partnership or S corporation, which is different than the net amount reported on the federal Schedule K-1.

Filing deadlines

State

Individual income tax returns must be either postmarked or e-filed by April 15, or by October 15 for extended returns. However, if either of these two dates falls on a weekend or legal holiday, the tax return or extension must be filed by the next day that is not a Saturday, Sunday, or legal holiday. Income tax returns should be mailed to:

Idaho State Tax Commission
PO Box 56
Boise ID 83756-0056

Federal

Taxpayers who live in Idaho and are mailing their federal individual income tax return, should mail it to the address listed on the Internal Revenue Service website.

E-filing

We recommend that taxpayers save time and postage by e-filing their tax returns and payments. Our Free Electronic Filing page lists several companies that offer free state and federal income tax filing.

Those who need help completing their tax returns can go to our Free Tax Help page, which lists neighborhood volunteer sites for all low-income taxpayers and senior citizens with simple returns.

Extension to file

If taxpayers can't file their Idaho individual income taxes by the April 15* due date, they may be eligible to get an automatic, six-month extension.

(*When April 15 falls on a weekend or holiday, the due date is moved to the next business day.)

To qualify, they need to pay either an estimated 80% of the tax they owe for the current tax year or 100% of what they paid for state income taxes the prior year, and they must pay it by April 15. (Taxpayers can complete the worksheet on Idaho Form 51, Estimated Payment of Idaho Individual Income Tax, and calculate the 80% to see if they meet the extension requirements.)

If an individual qualifies for an extension to file an Idaho return, the tax return and the balance of the filer's tax debt are both due by Oct. 15*. If the balance isn't paid in full at that time, we'll begin the collection process.

(*When Oct. 15 falls on a weekend or holiday, the due date is moved to the next business day.)

Those who qualify for an extension to file won't be charged a penalty for late filing, but they will be charged interest on the remaining tax until it's paid.

To make a payment and avoid a penalty, taxpayers can either:

• Mail Form 51 with a check or money order; or
• Make an online credit card payment through this website.

Amending a return

Sometimes it's necessary to change, correct, or update a return that's already been filed. To do this, the income tax return must be "amended," which is generally done by mail. However, the amended return can be filed electronically if the original return was filed electronically. Here are the steps for amending an Idaho income tax return:

1. Select the right form — Full-year Idaho residents must amend income tax returns by completing a corrected Form 40. Part-year Idaho residents and Idaho nonresidents must complete a corrected Form 43.
2. Check the box for an amended return in the upper-left corner of the page, complete the form, and attach information that explains why the return is being ameneded.
3. Attach the following documents to your Idaho amended return:
   • A full copy of Form 1040X if your federal return was amended,
   • Copies of all 1099s and/or W-2s that weren't included with the orginal return, and
   • Any required payment.

Refunds

There's a three-year expiration date for claiming a refund, beginning on the original due date of your income tax return. The "original due date" is the April 15 following the tax year (except when it falls on a weekend or holiday). Extensions of time to file don't change the original due date for the three-year refund claim period; after that time, a refund won't be issued.

Taxpayers can track their refund status during processing, by visiting Where's my refund? If the refund is less than expected, it could be due to unpaid court fines, child support, or other legal obligations.

More individual income tax information

• Watch our video, How to Get Your Payment Applied Correctly.
• See our Military page for service member and military family-specific tax information.
• See Seniors and Retirees about retirement income and benefits deductions.
• See Estates and Taxes for estates with gross incomes greater than $600 in a tax year.
• See Noncitizens about filing requirements for resident and nonresident aliens.
• Read about capital gains.
• Be informed about identity theft.
• Read the Idaho medical savings account brochure about saving for medical expenses while lowering the Idaho income tax you owe.
• Learn about IDeal, Idaho's college savings program, a 529 plan to save and pay for higher education while lowering the Idaho income tax you owe.
• If you earned less income this year, visit the IRS website to see if you qualify for the federal government's Earned Income Tax Credit (EIC).
• Forgot to file?

Laws and rules

• Income Tax Law: Chapter 30, Income Tax
• Income Tax Administrative Rules [PDF]
• Any proposed or temporary rules can be seen through this page.

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Last updated April 24, 2013