State of Idaho Personal Income Tax Extensions

E-file an IRS personal tax extension with

eFile a Personal Federal Tax Extension

IRS Form 4868


Now only $29.95

General Instructions

Idaho individual income tax returns are due by the 15th day of the 4th month after the end of the tax year. For calendar year taxpayers, this deadline is April 15. If you cannot file by that date, you can request a state tax extension. An Idaho personal extension will give you 6 more months to file your return, which moves the deadline to October 15 (for calendar year filers).

Idaho tax extensions are automatic, which means there is nothing to file with the State Tax Commission unless you owe Idaho income tax. If you have a state tax balance, it needs to be addressed before an extension can be granted. In order to get an Idaho tax extension, you need to fulfill one of the following requirements:

• Pay at least 80% of your current year estimated tax liability by the original deadline (April 15), or

• Pay 100% of your prior year's "Total Tax" by the deadline (April 15)

Use Idaho Form 51 (Estimated Payment of Idaho Individual Income Tax) to make a state extension payment. If you’re unsure whether you owe Idaho tax or you want to calculate your 80% extension requirement, fill out the worksheet on Form 51. You can mail your payment using Form 51 or pay online with Idaho’s E-Pay system:

Remember that failing to pay your Idaho taxes on time can result in penalty charges. Also note that you aren’t required to make an extension payment if your tax balance is $50 or less. However, interest will be assessed on any tax that isn’t paid by the original deadline.

Idaho’s E-File system:

For more information, please visit the Idaho State Tax Commission website:

Idaho State Income Tax Payment Forms

Form 51 (Estimated Payment of Idaho Individual Income Tax)

Mail Form 51 with payment to the following address:

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