Idaho I Business State Tax Extension I Corporations

• Idaho grants you an automatic 6-month extension to file your business tax return.
• The extension is NOT an extension to pay any taxes you may have due. Tax payments are due by the original return due date.
• To avoid a penalty, tax payments must be at least 80% of the current year’s tax liability or 100% of the prior year’s tax liability.

Idaho State Tax Commission
P.O. Box 83784
Boise, ID 83707-3784

Greater of $10 or 5% per month, not to exceed 25% when combined with penalties for:

• failure to pay;
• substantial understatement; and
• negligence.

0.5% of tax per month, not to exceed 25% when combined with penalties imposed for:

• failure to file;
• substantial understatement; and
• negligence.