Due date
File your return and pay any tax on or before the 15th day of the fourth month following the close of your tax year.
- For a calendar year filer, this is April 15.
- If the last day for filing a return falls on a Saturday, Sunday, or legal holiday, the return is on time if you file it on the next business day.
Please contact us if you forgot to file a tax return.
E-File
The Tax Commission, with the IRS, provides electronic filing of federal and state corporation income tax returns.
These software companies provide electronic filing of business income tax forms
Form ID K-1
Use Form ID K-1 to provide the partner, shareholder, or beneficiary of a pass-through entity with information required to complete the pass-through owner’s Idaho income tax return.
Bonus Depreciation
Depreciation is a federal income tax deduction that lets a taxpayer recover the cost of capital expenditures over time. Read our guide on bonus depreciation.
Combined reporting
Visit our Combined Reporting page.
Payment options
You can pay your business income tax in one of three ways:
- Include payment when filing your return.
- Pay securely online with Quick Pay through our Taxpayer Access Point (TAP) at tax.idaho.gov/quickpay.
- Visit tax.idaho.gov/epay for more information about other electronic payments.
- Fill out and mail in the following form:
Form ID-VP – Income Tax Voucher Payment
Extension
Need more time to file? See if you qualify. Read our guide on valid extensions for filing.
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 payments made after the original due date.