IFTA Basics: Quarterly Fuel-Tax Filing Explained

You bought fuel in Tennessee, drove 200 miles into Kentucky, and filled up there. Which state gets the tax?

That’s what IFTA solves. It’s not a federal tax—it’s an agreement between 48 U.S. states and Canadian provinces that lets carriers pay fuel tax based on where you actually drove, not just where you bought fuel.

For new carriers, IFTA seems complicated. It’s not—but the filing deadlines are strict, and most audit failures come from one source: bad mileage records.

What IFTA Is (Plain English)

IFTA (International Fuel Tax Agreement) reconciles fuel tax owed across the states and provinces where your carrier actually operates, based on two numbers:

Miles driven per jurisdiction (where you were operating)
Fuel purchased per jurisdiction (where you filled up)

The system credits you for fuel purchased in high-tax states and balances it against miles driven in low-tax states. What you owe is the difference.

Example: You buy 500 gallons in California (high tax rate), but your trips mostly go through Nevada (lower rate). IFTA calculates the net fuel-tax liability across both jurisdictions so you don’t overpay.

Who Needs IFTA

You need IFTA if your vehicle meets both of these criteria:

Vehicle qualifies — 2 or more axles with a Gross Vehicle Weight Rating (GVWR) over 26,000 lbs, OR 3 or more axles regardless of weight.
Operating in 2+ jurisdictions — You drove in more than one IFTA member state or province in the same quarter.

Most small carriers with 1–25 trucks fall into this category the moment they cross a state line.

If you only operate within a single state, check your state’s motor-fuel tax rules—you may not need IFTA, but you likely owe fuel tax differently (to that state directly).

IFTA Filing Deadlines (Quarterly)

IFTA reports are filed quarterly, with due dates tied to the calendar quarter:

Quarter	Due Date	Notes
Q1 (Jan–Mar)	April 30	Files for Jan, Feb, Mar activity
Q2 (Apr–Jun)	July 31	Files for Apr, May, Jun activity
Q3 (Jul–Sep)	October 31	Files for Jul, Aug, Sep activity
Q4 (Oct–Dec)	January 31 (next year)	Files for Oct, Nov, Dec activity

Important: Deadlines move around weekends and holidays. If the due date falls on a Saturday, Sunday, or federal holiday, it shifts to the next business day.

Example: Q3 2026 due date is October 31, which falls on a Saturday. The actual deadline is Monday, November 2, 2026.

Always check your state’s IFTA page before filing to confirm the exact due date, especially around holiday weekends.

What You Need to File

IFTA requires two things:

1. Trip Records

For every trip, you need:

Origin and destination (city/state)
Route taken (which jurisdictions you passed through)
Miles driven per jurisdiction (the critical part)

This doesn’t require fancy software. A notebook works if you’re disciplined. A spreadsheet is better. A GPS fleet-tracking system is best because it calculates miles per state automatically.

2. Fuel Receipts

Keep every fuel receipt showing:

Date
Amount of fuel purchased (gallons)
Price and total
Location (state/province)

This is straightforward—hold onto your pump receipts.

The Audit Landmine: Mileage Records

IFTA audits fail most often on mileage records. Not fuel records. Not tax calculations. Mileage.

Why? Because without solid mileage data, there’s no way to verify that your miles-driven-per-state claim is correct. An auditor can see you bought fuel in Tennessee, but if you can’t prove you drove 150 miles in Kentucky (not 50, not 300), they’ll estimate conservatively—which means you owe more tax.

The fix: Start day one with a trip log. At minimum, write down:

Where you started
Where you ended
Mileage (use your odometer or GPS)
Date

If you’re running 10+ trucks, fleet-tracking software that logs GPS position and calculates state-by-state miles automatically is worth the investment. One audit failure can cost thousands—the software pays for itself.

IFTA in Practice: A Simple Workflow

During the quarter:

Driver (or you) logs each trip: origin, destination, estimated miles per state.
Driver (or you) keeps fuel receipts and notes the state and gallons.
At the end of the month, reconcile odometer/GPS data with your trip log.

Before the filing deadline:

Tally total miles per jurisdiction for the quarter.
Tally total fuel purchased per jurisdiction for the quarter.
Use your state’s IFTA portal or an accounting software to file the report.
Pay any balance due (or claim a refund if you overpaid).

After filing:

Keep filed reports and supporting documents (fuel receipts, trip logs, tax payments) for at least 3 years. IFTA audits often reach back multiple years.

Late Filing Penalties

Miss an IFTA deadline? The penalties are immediate and add up fast.

Late filing penalty: Often 10% of the tax owed, plus interest (compounding daily).
Failure to remit: Additional penalties on top of the late fee.

Example: If you owe $1,000 in fuel tax and file 30 days late, you might owe $1,000 + $100 (penalty) + $15 (interest), plus administrative fees. It’s not devastating for one quarter, but it spirals if you miss multiple deadlines.

Missing an IFTA deadline also triggers notices from the IRS and state tax agencies. Your best move: mark the deadline in your compliance calendar three weeks early and file on time.

IFTA vs. State Fuel Tax

Some states impose additional fuel taxes outside IFTA. For example, if you operate exclusively in one state, you may need to file state fuel-tax reports separately from IFTA.

Check your primary operating state’s Department of Revenue website for state-specific fuel-tax rules. They exist alongside IFTA, not instead of it.

Fuel-tax rates differ from one jurisdiction to the next and are revised every quarter. For the authoritative figures, consult IFTA, Inc.’s official tax rate matrix, which publishes the current rate for every member state and Canadian province ahead of each quarter. Reviewing it gives you a clear picture of how fuel-tax rates compare across the states you operate in.

Getting Started

Get an IFTA license through your base state’s Department of Revenue. This is separate from your MC number and is tied to specific vehicles.
Choose a record-keeping method. A spreadsheet works today. Upgrade to fleet-tracking software as you scale.
Mark your calendar: 3 weeks before each quarterly due date, set a reminder to compile your records.
Keep receipts and logs for 3+ years. You don’t need to keep them forever, but regulators can audit back several years, so err on the side of keeping records longer.
File on time, every quarter. Penalties are steep, and late filings trigger a cascade of notices.

Common IFTA Questions

Q: What if I only drive in one state for a whole quarter?
A: You don’t need to file IFTA for that quarter. But if any quarter has activity in 2+ jurisdictions, you do file for that quarter. Keep your records clear so you know when filing is required.

Q: Can I use fuel purchased in one state to “count” as miles in another?
A: No. IFTA reconciles miles driven against fuel purchased, but they’re tracked separately. You can’t game the system by buying fuel cheap and claiming miles everywhere else.

Q: What if I’m part of a larger carrier or fleet?
A: Each separate MC number (authority) files its own IFTA. If you’re a single-truck operator under one MC, you file one IFTA per quarter.

Q: What if I’m buying fuel for other trucks?
A: Track it separately by driver or vehicle. Fuel receipts should clearly show which vehicle was filled. If you can’t tie fuel to a specific vehicle, auditors will assume the worst.

Next Steps

→ Compliance Calendar: Add IFTA Deadlines to Your Compliance Calendar
→ Finding Loads: Building Your First Route (and Tracking Miles)

IFTA is routine once you’re on a system. The pain point is the first year when you’re building the habit of logging every trip and keeping every receipt. After that, it’s 30 minutes per quarter to compile and file. Don’t skip it—penalties are expensive and compliance history matters when auditors come knocking.