Tennessee IFTA Tax Rate — 2026

How Tennessee IFTA tax is calculated

For every gallon of diesel your truck "burned" inside Tennessee during the quarter, you owe $0.2700 in IFTA tax. The number of taxable gallons isn't the gallons you bought there — it's the miles you drove inside Tennessee divided by your fleet's average miles-per-gallon for the whole quarter.

Your IFTA return then nets that against the Tennessee fuel-tax you already paid at the pump on gallons purchased inside the state. If you ran more Tennessee miles than you bought Tennessee fuel, you owe the difference. If you bought more Tennessee fuel than you ran Tennessee miles, you get a refund or credit.

Common Tennessee IFTA filing questions

• Do I file IFTA in Tennessee if my home base is here? If your IFTA base jurisdiction is Tennessee, you file your quarterly return with the Tennessee Department of Revenue (or equivalent). Your filing covers every IFTA jurisdiction you ran in, not just Tennessee.
• What if I only drove a few miles through Tennessee? Every IFTA mile counts, even if you only crossed the state. Track them on your trip sheet or ELD report — you'll owe (or get refunded) Tennessee's share whether you bought fuel here or not.
• What if Tennessee fuel is cheaper than the IFTA tax? The IFTA rate above is what you owe per gallon "consumed" in Tennessee. The pump price already includes Tennessee's state fuel tax — that's what gets credited on your return. If you bought all your fuel in a low-tax state and drove all your miles in Tennessee, you'll owe the full Tennessee rate on those gallons at filing time.

Tennessee IFTA filing deadlines

IFTA returns are due quarterly across all 48 contiguous U.S. states, including Tennessee:

• Q1 (Jan–Mar): due April 30
• Q2 (Apr–Jun): due July 31
• Q3 (Jul–Sep): due October 31
• Q4 (Oct–Dec): due January 31

Late filings collect penalties even if you owe nothing — some states charge $50 minimum per late return. File on time even if your net due is $0.