Idaho Filing Due Date: Business tax returns are due by April 15 — or by the 15th day of the 4th month following the close of the taxable year (for fiscal year filers).
Extended Deadline with Idaho Tax Extension: Idaho offers a 6-month extension, moving the filing deadline to October 15 (for calendar year filers).
Idaho Tax Extension Form: Idaho business extensions are automatic, which means there is no application or written request to submit.
Idaho Extension Payment Requirement: An extension of time to file is not an extension of time to pay. To avoid interest and penalties, your Idaho tax balance must be paid by the original due date. In order to obtain an Idaho extension, you must fulfill the extension payment provision by paying (at least) 80% of your current year tax liability or 100% of your prior year tax liability.
You can make an Idaho extension payment with Form 41ES, or pay electronically via Idaho’s E-Pay center: tax.idaho.gov/e-pay
Idaho Tax Extension Tip: You don’t need to make an extension payment if you owe $50 or less in Idaho tax. But any unpaid tax will be subject to interest after the April 15 deadline.