State of Idaho
Personal Income Tax Extensions
Modified 2019 Tax Return Due Date: July 31, 2020
Idaho Filing Due Date: Individual income tax returns are due by April 15 — or by the 15th day of the 4th month following the end of the taxable year (for fiscal year filers).
Extended Deadline with Idaho Tax Extension: Idaho offers a 6-month extension, which moves the filing deadline from April 15 to October 15 (for calendar year filers).
Idaho Tax Extension Form: Idaho tax extensions are automatic, which means there is no application or written request to submit. As long as you’ve met Idaho’s extension payment requirement (see below), you will automatically receive a state tax extension.
Idaho Extension Payment Requirement: An extension of time to file is not an extension of time to pay your Idaho income tax. All state tax payments are due by the original deadline of the return. Any Idaho tax that isn’t paid by the proper due date will be subject to interest and penalties. In order to be granted an automatic state extension, you must pay (at least) 80% of your estimated Idaho tax liability for the taxable year or 100% of your previous year’s "Total Tax" by the original deadline.
You can make an Idaho extension payment with Form 51, or pay electronically using Idaho’s “E-Pay” system: tax.idaho.gov/e-pay
Idaho Tax Extension Tip: You are not required to submit an extension payment if your Idaho tax liability $50 or less. But keep in mind, interest will accumulate on any tax not paid by the original due date.