Idaho State Tax Commission

Idaho State Tax Commission

Penalty & Interest Estimator

Tax type: Income tax for a business (Forms 41, 41S, 65, or 66)

Step 1 of 5: Valid extension?

(See Form 51 for individuals' income tax or Form 41ES for businesses' income tax)

Learn more about a valid extension of time.

Step 2 of 5: Enter your tax due

…or STOP! and start over »

Last updated January 11, 2018

The information on this site is for general guidance only. Tax laws are complex and change regularly. We can't cover every circumstance in our website guides. We work to provide current and accurate information on our website. But some information could have technical inaccuracies or typographical errors. If there's a conflict between current tax law and the information on our website, current tax law will govern.