gov revenue formsandresources forms EXT-08_fill-in

This document provides instructions for calculating an extension payment for Montana individual income tax for tax year 2008. It explains how to determine the payment amount owed by April 15, 2009 in order to receive an extension to file the tax return. The form walks through a worksheet to calculate the payment as the smaller of 100% of the 2007 tax liability or 90% of the calculated 2008 tax liability, less credits and payments made. It stresses that an extension to file is not an extension to pay, so penalties and interest will apply to any unpaid amounts by the deadline.