IFTA Tax Credits by State: Where to Buy Fuel to Maximize Refunds

Every gallon of diesel you buy includes state fuel tax baked into the pump price. Under IFTA, that tax becomes a credit on your quarterly return — a dollar-for-dollar offset against the fuel tax you owe based on miles driven in each state. The carriers who understand how these credits work, and who fuel strategically, can reduce their net IFTA liability by hundreds or even thousands of dollars per quarter.

This guide breaks down how IFTA tax credits work by state, identifies the highest and lowest tax rate jurisdictions, and provides practical fueling strategies for common routes that can maximize your refunds.

In this guide, you will learn:

• How IFTA fuel tax credits are calculated by state
• Which states have the highest and lowest fuel tax rates
• How to fuel strategically to maximize credits and minimize net tax
• Practical fueling strategies for common interstate routes
• Common mistakes that leave credit money on the table

How IFTA Credits Work: The Basics

IFTA is a reconciliation system. For each state you operate in, two numbers are compared:

1. Tax owed = Miles driven in that state ÷ your fleet MPG × that state's tax rate per gallon
2. Tax credit = Gallons purchased in that state × that state's tax rate per gallon

If you bought more fuel in a state than your miles consumed (based on your fleet MPG), that state owes you a refund. If you drove more miles than your fuel purchases cover, you owe that state additional tax. Your IFTA return nets all of this out across every jurisdiction.

The key insight is this: buying fuel in a high-tax state generates a larger credit per gallon than buying fuel in a low-tax state. If you're going to buy fuel anyway, buying it where the tax rate is highest gives you the biggest credit to offset what you owe.

State Fuel Tax Rates: The Credit Multiplier

Not all states tax diesel equally. The difference between the highest and lowest state diesel tax rates is substantial — often more than $0.40 per gallon. Here are the top 10 highest and lowest diesel tax rate states as of 2026 (rates change quarterly; always verify current rates before filing):

Top 10 Highest Diesel Tax Rate States

Top 10 Lowest Diesel Tax Rate States

Note: Rates shown are approximate and subject to quarterly adjustments. Always verify current rates through your base jurisdiction or IFTA Inc. before making fueling decisions or filing returns.

The Math Behind Strategic Fueling

Let's walk through a concrete example. Suppose you drive 500 miles through Pennsylvania and 500 miles through Texas, and your truck averages 6.0 MPG. You need to buy roughly 167 gallons total for this trip.

Scenario A: Buy all fuel in Texas

• Pennsylvania tax owed: 500 miles ÷ 6.0 MPG × $0.741 = $61.75
• Pennsylvania credit: 0 gallons × $0.741 = $0.00
• Texas tax owed: 500 miles ÷ 6.0 MPG × $0.200 = $16.67
• Texas credit: 167 gallons × $0.200 = $33.40
• Net IFTA due: $61.75 + $16.67 − $0.00 − $33.40 = $45.02

Scenario B: Buy all fuel in Pennsylvania

• Pennsylvania tax owed: 500 miles ÷ 6.0 MPG × $0.741 = $61.75
• Pennsylvania credit: 167 gallons × $0.741 = $123.75
• Texas tax owed: 500 miles ÷ 6.0 MPG × $0.200 = $16.67
• Texas credit: 0 gallons × $0.200 = $0.00
• Net IFTA due: $61.75 + $16.67 − $123.75 − $0.00 = −$45.33 (refund)

Same trip, same total fuel consumption — but a $90.35 difference in net IFTA tax simply based on where you bought fuel. Scale that across a full quarter with multiple trucks, and strategic fueling becomes a meaningful cost savings.

Fueling Strategies for Common Routes

I-95 Corridor (Southeast to Northeast)

The I-95 corridor runs from Florida through the mid-Atlantic and into New England, passing through states with widely varying tax rates. The strategy here is straightforward:

• Maximize fuel purchases in: Pennsylvania ($0.741), Connecticut ($0.492), New York ($0.484), New Jersey ($0.445)
• Minimize fuel purchases in: South Carolina ($0.280), Virginia ($0.302), Georgia ($0.331)
• Practical tip: Fill up when entering or exiting Pennsylvania. The PA Turnpike has several truck stops with competitive base prices despite the higher tax.

I-80 Cross-Country (East to West)

I-80 crosses the northern tier from New Jersey to California, making it one of the most common cross-country routes for freight.

• Maximize fuel purchases in: Pennsylvania ($0.741), Indiana ($0.560), Illinois ($0.467), New Jersey ($0.445)
• Minimize fuel purchases in: Wyoming ($0.240), Nebraska ($0.268), Iowa ($0.325)
• Practical tip: Top off before leaving Indiana heading west. The next high-tax state isn't until you reach California or Washington on alternate routes.

Southeast Loop (TX – LA – MS – AL – GA – FL)

The Southeast is dominated by low-tax states, making it harder to generate significant credits. Your strategy shifts to damage control:

• Maximize fuel purchases in: Georgia ($0.331), Alabama ($0.310), Florida ($0.345) — the “least low” rates in the region
• Minimize fuel purchases in: Texas ($0.200), Mississippi ($0.180), Louisiana ($0.200)
• Practical tip: If your route extends north, hold off fueling until you reach North Carolina ($0.422) or further north.

Midwest Hub Routes (Chicago, Indianapolis, Columbus)

The Midwest has some surprisingly high-tax states that create good credit opportunities:

• Maximize fuel purchases in: Indiana ($0.560), Illinois ($0.467), Ohio ($0.385)
• Minimize fuel purchases in: Missouri ($0.195), Iowa ($0.325), Kansas ($0.260)
• Practical tip: Indiana is the credit sweet spot of the Midwest. Any time you pass through on I-65, I-70, or I-80, fill up.

Important Caveats About Strategic Fueling

Strategic fueling can save money, but it needs to be balanced against practical reality:

• Base fuel prices matter — A state with a high tax rate but also high base fuel prices may not save you money overall. Pennsylvania has the highest tax, but its base price is often lower than California's.
• Don't run empty chasing credits — Running your tank low to reach a high-tax state is dangerous and can strand you. Safety always comes first.
• Route efficiency trumps tax strategy — Driving extra miles to fuel in a high-tax state costs more in fuel, time, and wear than the credit savings. The strategy only works when the high-tax stop is already on or near your route.
• Your fleet MPG stays the same — Strategic fueling changes where your credits land, not your total fuel consumption. Your overall fuel cost is driven by miles, MPG, and base price — not tax strategy.
• Keep every receipt — Credits only count if you can document them. A lost receipt in a high-tax state is the most expensive receipt to lose.

How Credits Appear on Your IFTA Return

On your quarterly return, each state has its own line showing:

1. Taxable miles — Miles driven in that state.
2. Taxable gallons — Miles ÷ fleet MPG = gallons “consumed” in that state.
3. Tax-paid gallons — Gallons actually purchased in that state (your credit basis).
4. Net taxable gallons — Taxable gallons minus tax-paid gallons. Positive means you owe; negative means you get a credit.
5. Tax or credit amount — Net taxable gallons × state tax rate.

The bottom line of your return sums all states. If credits exceed taxes owed, you receive a refund check from your base jurisdiction. If taxes owed exceed credits, you remit the difference with your return.

Frequently Asked Questions

Do I get credits for fuel purchased in a state I didn't drive through?

No. IFTA credits only apply to jurisdictions where you both purchased fuel and drove miles. If you buy fuel in a state you don't drive through during the quarter, those gallons don't generate a credit on your IFTA return for that state. However, all fuel purchases contribute to your fleet MPG calculation, which affects taxable gallons in every state.

Can I claim credits without receipts?

Generally, no. IFTA requires documentation for every fuel purchase you claim as a credit. Acceptable documentation includes fuel receipts, fleet card transaction records, or bulk fuel purchase records with proper detail. During an audit, undocumented fuel purchases will be disallowed, and you'll lose those credits.

Do Canadian provinces work the same way?

Yes. The 10 Canadian provinces that participate in IFTA follow the same credit system. Fuel purchased in a province generates a credit against miles driven in that province. Canadian tax rates and surcharges vary by province, and exchange rate conversions apply when calculating credits for cross-border operations.

How much can strategic fueling realistically save?

For a single truck running 100,000–120,000 miles per year, strategic fueling adjustments can reduce net IFTA tax by $500–$2,000 annually, depending on routes and how much flexibility you have in choosing fuel stops. For a 10-truck fleet, that's $5,000–$20,000 per year.

Bottom Line

IFTA credits are not something that just happens to you — they're a variable you can influence with informed fueling decisions. Understanding which states offer the highest credit per gallon, and prioritizing those states when you need to fill up, is one of the simplest ways to reduce your quarterly tax liability.

FleetCollect tracks every fuel stop with date, location, gallons, and state — giving you a clear picture of where your credits are coming from and helping you spot opportunities to fuel smarter on future trips.