What is the current interest rate assessed or paid by the Department of Revenue?
The current interest rate is 8%, and it will continue to be in effect through December 31, 2010. Under Montana law, the interest rate for all unpaid taxes depends on the rate set by the Internal Revenue Service (IRS) and may fluctuate each year, but will not be less than 8%. Interest accrues from the original due date. For income tax refunds, the department pays interest to taxpayers on refunds of original returns 90 days after the due date. If a return is filed late, interest is paid 90 days after the return is filed.
