Idaho State Tax Commission

Business Income Tax

You must file income tax returns for your business entity if any of the following are true:

  • You're transacting business in Idaho.
  • You're registered with the Idaho Secretary of State to do business in Idaho.
  • You have income attributable to Idaho.
  • You're a fiduciary.

Transacting business in Idaho is indicated by, but not limited to, the following activities:

  • You own or lease, as lessor or lessee, any property in Idaho.
  • You solicit business in Idaho.
  • You are a member of a partnership or S corporation with business in Idaho.
  • You have any Idaho activity from which you receive, realize or derive income.
  • You have an agent — such as a collector, repair person, or delivery person — acting on your behalf in Idaho.


You can choose to file electronically, saving time and postage. These companies provide electronic filing of business income tax forms.

Otherwise, you can file using paper forms:

Tax rates

The Idaho business tax rate is on taxable income. Below is a history of tax rates:

2022 6%
2021 6.5%
2018-2020 6.925%
2012-2017 7.4%
2001-2011 7.6%

Business Entities

Review these resources for more in-depth information:

Permanent Building Fund (PBF) tax

Most businesses must pay the $10 PBF tax. These businesses include:

  • C corporations must pay the $10 tax.
  • A unitary group of corporations must pay $10 for each corporation required to file in Idaho, whether the corporations file individually or the unitary group includes them in a group return.
  • S corporations must pay $10 for each shareholder it pays the Idaho income tax for.
  • Partnerships must pay $10 for each partner it pays the Idaho income tax for.
  • Estates and trusts must pay $10 for each beneficiary it pays the Idaho income tax for.

See Idaho Code section 63-3082.

Related documents

Visit the Income Tax Hub for links to related guides.

Keeping records

Keep copies of your tax returns and all supporting documentation for a minimum of seven years. Businesses exercising the option to carry back or carry forward need to keep records for all affected years.

Laws and rules

Learn more about Idaho business income tax:

Last updated August 10, 2022. Last full review of page: August 29, 2019

This information is for general guidance only. Tax laws are complex and change regularly. We can't cover every circumstance in our guides. This guidance may not apply to your situation. Please contact us with any questions. We work to provide current and accurate information. But some information could have technical inaccuracies or typographical errors. If there's a conflict between current tax law and this information, current tax law will govern.