personal income tax
You must file individual idaho income tax returns if you are any of the following:
- idaho resident
- idaho resident part of the year with income from idaho sources or income earned while an idaho resident
- non-idaho resident with income from idaho fonts
see “filing requirement” below.
check out these resources for more detailed information:
- idaho source of income
- idaho state of residence
- income tax center
presentation
You can choose to file electronically, saving time and shipping costs.
- These tax software packages allow you to prepare and electronically file your federal and idaho individual income tax forms for free if you meet certain criteria.
if you don’t qualify for free filing or don’t want to use the tax software:
- find all current year idaho individual income tax forms here.
- find all prior year idaho individual income tax forms here.
Need more time to apply? see if you qualify read our guide on valid extensions to file.
refunds
You must file a return within three years of the original due date (often April 15), or any refund due to you for that return will lapse. You still need to file your tax return if you’re past the three-year limit, but we won’t be able to issue a refund.
- see: where is my new refund video?
- what slows down your refund?
modified declarations
Double check your tax return before you mail it or submit it through an online e-filing service. (note: an amended return may delay the completion of other returns being processed).
If you need to correct a previously filed return, follow these steps to file an amended return:
- Check which return you originally filed: Form 40 or Form 43. Download a blank copy.
- Check the modified box at the top of the blank return.
- complete the declaration as it should have been filled out.
- attach an explanation of why you are modifying the declaration.
- If necessary, include copies of any forms or schedules missing from the original filing.
- If your federal return was amended, attach a copy of Form 1040x.
- mail your amended return, any supporting documentation, and any payments due to: idaho state tax commission, post office box 56, boise id 83756-0056.
requirement to submit
You must file a return if your gross income is over a certain amount (see below). gross income means all income from all sources before expenses or deductions are applied. This income includes wages, interest, rent, dividends, proceeds from property sales, and gross business income.
read our guide to idaho sources of income and our income tax instructions (see next section) for more information.
idaho residents
Form 40 is the idaho income tax return for idaho residents. instructions are in a separate file.
Idaho residents must apply if their gross income for 2021 is at least:
age on the last day of 2021.
residents of idaho for part of the year
Form 43 is the idaho income tax return for part-year residents of idaho. instructions are in a separate file.
part-year idaho residents must apply if their total gross income from the following sources combined is greater than $2,500:
- all sources while idaho resident
- income from idaho sources while non-resident
non-residents
Form 43 is the idaho income tax return for nonresidents with idaho source income. instructions are in a separate file.
Non-residents of idaho must apply if their total gross income from idaho sources exceeds $2,500.
Find detailed examples in our Idaho Residency Status and Idaho Source of Income guides.
tax rates
2021 income tax rates range from 1% to 6.5% on idaho taxable income. The personal income tax is graduated. This means that idaho taxes higher earnings at a higher rate.
keep records
Keep copies of your tax returns and all supporting documentation for at least seven years.
laws and regulations
learn more about idaho individual income tax:
- Idaho Code Title 63, Chapter 30 – Income Tax
- Income Tax Rules
page last updated on August 10, 2022. page last full revision: October 9, 2019