Business Income Tax Guides

Click on a column heading to sort the list by the contents of that column.

Guide Name Revision Date
Recommended Formula for the Apportionment and Allocation Of Net Income of Financial Institutions 05-25-2023
Business and Individual E-File (MeF) Handbook 2025 12-05-2025
Audits - Your Rights and Responsibilities 06-26-2024
Combined Reporting Example 09-13-2018
How Your Income Tax Penalty Is Calculated 07-06-2016
Conformity and Tax Reform 04-30-2018
Idaho Taxpayer Rights 08-27-2019
Calculating Idaho Distributable Income for Pass-through Entities (PTE) 08-15-2023
Pass-through reporting requirements flowchart 09-07-2023

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:

Business Income

Basics and Tax Rate

Certain Taxpayer Guides

Filing and Paying

Forms

Other Guides

Recordkeeping

Laws and Rules

VDA

Voluntary Disclosure Agreement