Send your letter of request to the Idaho State Tax Commission, Account Registration and Maintenance Section, PO Box 36, Boise, Idaho 83722. Your letter of request must be approved by all member jurisdictions in which you travel. You are required to file your return by the due date. You must file each return even if you do not have taxable fuel or travel in Idaho or in any other IFTA jurisdictions. Information regarding IFTA jurisdictions, tax rate changes, and other administrative changes by each jurisdiction will accompany your Form 3150 .
Interest is calculated for each jurisdiction that has tax due.
Even if you have a net refund, interest still applies jurisdiction by jurisdiction for any underpayment of fuels use tax. To avoid penalty for late filing, the tax return must be postmarked no later than midnight on the last day of the month following the close of the filing period. If a return is hand delivered, it is considered received on the date that it is delivered to the Idaho State Tax Commission. If the due date is on a weekend or holiday, the return is due on the next business day. If you discover that you have incorrectly reported any information on your regular quarterly or annual IFTA return, you may correct the errors by filing an Amended IFTA Return, Form 3170 .