# IFTA (International Fuel Tax Agreement)

> IFTA (International Fuel Tax Agreement) is the agreement among the 48 contiguous US states and 10 Canadian provinces under which an interstate carrier licenses in one base jurisdiction and files one quarterly fuel-tax return that splits the tax by miles driven in each jurisdiction.

Without IFTA, a truck crossing ten states would owe fuel tax returns in ten places. With it, the carrier files once with its base jurisdiction, which collects the tax due to every member and distributes it. IFTA applies to a qualified motor vehicle: one with two axles and a gross or registered weight over 26,000 lb, three or more axles regardless of weight, or a combination weighing over 26,000 lb. Recreational vehicles are excluded.

Each quarter the return reconciles where fuel was bought with where it was burned. The fleet’s average miles per gallon (to two decimals) converts the taxable miles in each jurisdiction into taxable gallons; gallons already bought there with tax paid are subtracted; the difference is multiplied by that jurisdiction’s rate for the quarter. The result is a payment to some states and a credit from others.

Accurate miles per state are the hard part, which is why carriers take them from GPS or ELD data rather than from dispatch estimates. The free [IFTA calculator](https://transportial.com/en-us/tools/ifta-calculator) applies the current quarter’s rates to your miles and fuel.

## IFTA due dates and penalties

Returns are due on the last day of the month after each quarter: April 30 (Q1), July 31 (Q2), October 31 (Q3) and January 31 (Q4). When that day falls on a weekend or legal holiday, the return is due the next business day, so the third-quarter 2026 return is due Monday, November 2, 2026. A return is required even if the vehicle did not operate or bought no fuel that quarter.

Late filing, not filing or underpaying costs a penalty of US$50 or 10% of the delinquent tax, whichever is greater, plus interest. Oregon is a special case: it uses a weight-mile tax for heavy trucks and shows no diesel rate in the IFTA matrix, so Oregon miles need a separate weight-mile report.

## Frequently asked questions

### Who has to file IFTA?

Carriers that operate a qualified motor vehicle (over 26,000 lb with two axles, three or more axles, or a combination over 26,000 lb) in two or more member jurisdictions. Intrastate-only operators and vehicles below the thresholds generally use trip permits or no permit instead.

### How is IFTA fuel tax calculated?

Divide total miles by total gallons for the fleet’s MPG. For each jurisdiction, divide its taxable miles by that MPG to get taxable gallons, subtract the tax-paid gallons you bought there, and multiply by the jurisdiction’s rate for the quarter. Add the results, including surcharge lines for Kentucky and Virginia.

### What is the difference between IFTA and IRP?

IFTA splits fuel tax by the miles driven in each jurisdiction and is filed every quarter. [IRP](https://transportial.com/en-us/glossary/irp) splits vehicle registration fees by distance and is renewed every year for an apportioned plate. Most interstate trucks need both.

### Can I file IFTA annually instead of quarterly?

Only with approval from your base jurisdiction, and only if the vehicle ran fewer than 5,000 miles (8,000 km) in all member jurisdictions other than the base jurisdiction over 12 consecutive months. Annual returns are due January 31.


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Canonical page: https://transportial.com/en-us/glossary/ifta