What IFTA is
The International Fuel Tax Agreement lets carriers file one quarterly fuel tax return with their base state instead of a return in every state. The base state then shares the tax among the others.
Who needs it
Qualified motor vehicles used across state lines: those over 26,000 lbs gross, or with three or more axles, traveling in two or more IFTA jurisdictions. You get a license and two decals per truck each year.
How the math works
- Fleet MPG = total miles in all states ÷ total gallons bought.
- Taxable gallons per state = miles in that state ÷ fleet MPG.
- Tax per state = (taxable gallons − gallons bought there) × that state's rate.
- Add them up. A positive total is owed; a negative total is a credit.
Try it with your own numbers in the IFTA calculator. Rates change every quarter, so use the current IFTA rate table.
Deadlines
| Quarter | Return due |
|---|---|
| Q1 (Jan–Mar) | April 30 |
| Q2 (Apr–Jun) | July 31 |
| Q3 (Jul–Sep) | October 31 |
| Q4 (Oct–Dec) | January 31 |
File even if you didn't run that quarter. Late returns bring penalties and interest.
Records to keep
- Miles by state from your ELD or trip sheets
- Every fuel receipt: date, location, gallons and price
- Keep records for four years. Audits ask for them.
Tips to pay less
Buying fuel in states with higher fuel tax, where you also drive a lot, earns credits that offset what you owe. Better fuel economy lowers taxable gallons everywhere. The fuel cost calculator helps you see the cost of every MPG point.
Common questions
When is IFTA due?
April 30, July 31, October 31 and January 31 for the four quarters.
Do I owe IFTA in a state where I didn't buy fuel?
Yes, if you drove there. IFTA taxes fuel by where it is burned.