What is IFTA in trucking? The plain answer, with the math

Who needs IFTA, and who doesn't

You need an IFTA license if you run a qualified motor vehicle in two or more member jurisdictions. Under the IFTA agreement, that means:

• two axles and a gross vehicle weight or registered gross vehicle weight over 26,000 lb (11,797 kg), or
• three or more axles at any weight, or
• a combination whose combined weight is over 26,000 lb.

So a tractor-trailer running between states needs IFTA. A two-axle 26 ft box truck rated at 26,000 lb or less does not, even when it crosses state lines. A hotshot depends on the combination: a dually pulling a 40 ft gooseneck is often rated over 26,000 lb combined and needs it. A tri-axle dump truck qualifies on axles alone, but only needs IFTA if it leaves its home state. Recreational vehicles are excluded.

Trucks that stay in one state don't need IFTA at all; they pay that state's fuel tax at the pump and follow its own rules.

How the IFTA return works

Every gallon of diesel you buy at a pump already includes that state's fuel tax. IFTA reshuffles that tax so each state gets paid for the miles you drove on its roads. Each quarter you report:

1. Miles in each jurisdiction, from your ELD or trip records.
2. Total gallons bought in the quarter, from your fuel receipts or card statements.
3. Your fleet fuel economy: total miles ÷ total gallons.
4. Taxable gallons per state: that state's miles ÷ your fuel economy.
5. Tax due per state: taxable gallons × the state's rate for the quarter.
6. Tax paid per state: gallons you bought there × the same rate.
7. The net: tax due minus tax paid. Positive means you owe that state; negative is a credit.

Your base jurisdiction adds up the lines, collects or credits the net, and pays the other states. You never file with Texas or Tennessee directly.

A worked IFTA return, line by line

Carrier A is made up. One truck, a quarter with 30,000 miles at 6.5 mpg (about 4,615 gallons), bought fuel in Texas, Oklahoma and Tennessee, and drove through Arkansas without filling up. Rates are real: the IFTA, Inc. matrix for 4Q 2026.

Source: IFTA, Inc., IFTA tax rate matrix, 4th quarter 2026 · checked Oct 2026

Read the net column. Carrier A bought more fuel in Texas and Oklahoma than the miles there used, so those states owe a credit. Arkansas got miles but no fuel purchases, so Carrier A owes Arkansas for every gallon burned there. The quarter nets to a small amount owed. That is IFTA in one table: you pay for the miles, wherever you happened to fill up.

What IFTA costs you

There are three parts, and only the last one is large:

• The license. Issued once, renewed yearly, by your base jurisdiction. Many charge nothing or a small fee.
• Decals. One set per truck per year, usually a few dollars a set.
• The net tax. Whatever the quarterly returns say you owe after credits for tax paid at the pump. This can be positive or negative each quarter.

Running the return yourself takes good records more than anything else. Fuel receipts that are missing, or miles that don't match your ELD, are the usual reasons an audit adds tax. Our guide to what IFTA reports contain shows the records that back each line, and the IFTA fuel tax calculator runs this whole table with your own miles and gallons.

When it is due

Returns are due the last day of the month after each quarter ends: April 30, July 31, October 31 and January 31. If the due date falls on a weekend or legal holiday, it moves to the next business day. File even if you didn't drive or owe nothing.

Late returns carry a penalty under the agreement: $50 or 10% of the net tax due, whichever is greater, plus interest on unpaid tax. The full year of trucking deadlines, IFTA alongside estimated taxes and Form 2290, is on the trucking tax deadlines calendar.

IFTA in your books

IFTA sits inside your bookkeeping, not beside it. The fuel tax you pay at the pump is part of your fuel cost; the net IFTA payment or credit each quarter adjusts it. Keep fuel receipts by quarter, reconcile miles monthly instead of once a quarter, and the return becomes arithmetic instead of archaeology. Where IFTA fits in the rest of the books is in accounting for trucking companies. If you would rather pay someone to file, compare options in IFTA filing services.

General information, not tax advice. Rules and rates change every year and depend on your situation: confirm with a tax professional before you file. We are not a tax preparer or accountant.

We don't file IFTA for carriers. What our truck dispatch service does is keep your miles and loads organized every week, so the quarter-end numbers are already on paper.