IFTA made simple: what every carrier needs to track

The International Fuel Tax Agreement (IFTA) exists so that carriers pay fuel tax to each state or province based on miles actually driven there — not just where they bought the diesel. It sounds complicated, but it comes down to tracking two numbers accurately and filing four times a year.

The two numbers that matter

1. Miles driven in each jurisdiction. Every state and Canadian province you run through, tracked separately, for every qualified vehicle.
2. Gallons of fuel purchased in each jurisdiction. Keep the receipts — the jurisdiction, date, gallons, and vehicle need to be defensible.

From those, the return calculates your fleet-wide average MPG, figures out how much fuel you burned in each jurisdiction, compares it to how much you bought there, and settles the difference — you either owe tax or get a credit per jurisdiction.

The quarterly rhythm

IFTA returns are due at the end of the month after each quarter closes: April 30, July 31, October 31, and January 31. File through your base jurisdiction even for a quarter with no miles — a missed "zero" return still draws penalties.

Where carriers lose money and time

Two mistakes are common. First, sloppy mileage records — estimating instead of using trip or ELD data — which fails an audit and usually overstates tax. Second, ignoring credits: if you bought more fuel in a state than you burned there, you're owed money, but only if the return captures it.

Make the return a five-minute job

The work isn't the math — it's assembling clean per-jurisdiction miles and gallons. Ziply Fleet pulls mileage from your ELD, organizes fuel purchases by jurisdiction, and calculates the IFTA return (plus OR/KY/NY/NM mileage taxes) for you, then keeps a filing history so your records are audit-ready.

This article is general information, not tax advice. Confirm deadlines and rules with your base jurisdiction.