State Guide

Montana IFTA, IRP, and Fuel-Use Tax Guide (2026)

If your fleet is based in Montana or operates through the state regularly, you'll need to understand how IFTA, IRP, and Montana fuel-use taxes apply to you. This guide covers the essentials.

Does Montana Participate in IFTA?

Yes. Montana is an IFTA member jurisdiction. If Montana is your base state, you file quarterly IFTA returns with the Montana Department of Transportation, reporting fuel use in all participating U.S. states and Canadian provinces. Official guidance is available from the Montana Department of Transportation.

Who Must Register for IFTA in Montana?

You generally must register for IFTA in Montana if you operate a qualified motor vehicle that:

  • Has two axles and a gross vehicle weight over 26,000 lbs, or
  • Has three or more axles regardless of weight, and
  • Travels in more than one IFTA member jurisdiction

The Montana Department of Transportation provides detailed criteria and registration instructions. Once registered, you receive an IFTA license and decals for each qualified vehicle.

Montana IFTA Reporting Periods and Due Dates

Montana follows the standard IFTA quarterly calendar:

  • Q1: January – March → due April 30
  • Q2: April – June → due July 31
  • Q3: July – September → due October 31
  • Q4: October – December → due January 31

If a due date falls on a weekend or legal holiday, your return is typically due the next business day. For the full schedule, see IFTA Reporting Periods and Due Dates.

How to File Montana IFTA Returns Online

Montana carriers can file IFTA returns electronically through the Montana Department of Transportation's online systems. When you use iFuelTax, you can:

  • Generate a report that matches Montana's required fields
  • Use that report as the basis for your online filing
  • Keep a copy of the return and supporting records in one place

This reduces the risk of data-entry errors when moving between systems.

How iFuelTax Simplifies Montana IFTA and Tax Compliance

With iFuelTax, Montana-based fleets can:

  • Centralize mileage and fuel data across the U.S. and Canada
  • Apply current IFTA rules automatically
  • Generate file-ready reports for every jurisdiction you operate in

Estimate your next bill with the free IFTA Mileage & Tax Calculator, or see how the pieces fit together in our IFTA vs IRP vs Weight-Distance guide. Browse other states from the IFTA by State directory.

Simplify Montana IFTA compliance

Centralize mileage and fuel data, apply current Montana rules automatically, and generate file-ready reports. Start your free trial.

Start Free TrialBook a Demo