IFTA Without the Scramble: Clean Mileage and Fuel Data

IFTA in plain terms

The International Fuel Tax Agreement lets a carrier license in one base jurisdiction and file a single quarterly fuel tax return covering every member jurisdiction it ran in. The members are the 48 contiguous U.S. states and the 10 Canadian provinces. Your base jurisdiction collects the return and distributes tax to, or refunds from, the others.

The idea is simple. Fuel tax is owed where fuel is burned, not where it is bought. So for each jurisdiction, the return compares the fuel you used there (based on miles driven and fleet fuel economy) with the tax-paid fuel you bought there. Where you used more than you bought, you owe. Where you bought more than you used, you get a credit.

Who has to file

In general, IFTA applies to qualified motor vehicles used in interstate operation: vehicles with two axles and a gross or registered gross vehicle weight over 26,000 pounds, vehicles with three or more axles regardless of weight, or combinations over 26,000 pounds combined weight. There are exceptions and special cases, such as recreational vehicles, so confirm your fleet's status with your base jurisdiction.

Quarterly deadlines

Returns are due on the last day of the month after each quarter ends. A return is generally required for every quarter you hold a license, even if a quarter had no operation in IFTA jurisdictions.

Late returns and late payments bring penalties and interest under the IFTA agreement, and repeated problems can put a license at risk. Some jurisdictions adjust due dates that fall on weekends or holidays; check with yours rather than assuming.

The calendar itself is not the problem for most carriers. The problem is that the data work starts after the quarter closes, when every gap is a month or more old and much harder to fix. The rest of this guide is about moving that work into the quarter.

How the return is calculated

Understanding the math shows you which data matters most. Here is the general calculation, with simple illustrative numbers that are not real tax rates or real fleet figures:

1. Fleet fuel economy. Total miles in all jurisdictions (IFTA and non-IFTA) divided by total gallons of that fuel type used. Example: 300,000 miles / 50,000 gallons = 6.0 MPG.
2. Taxable gallons per jurisdiction. Taxable miles in the jurisdiction divided by fleet MPG. Example: 60,000 miles in a state / 6.0 = 10,000 gallons used there.
3. Net taxable gallons. Gallons used there minus tax-paid gallons bought there. Example: 10,000 used minus 7,000 bought = 3,000 net gallons.
4. Tax due or credit. Net gallons times that jurisdiction's rate for the quarter (published quarterly). Positive means tax due; negative means a credit.

Two things jump out. First, miles drive everything: an error in total miles changes your MPG, which changes every jurisdiction's line. Second, every gallon without proper documentation is a gallon you cannot credit, which means paying tax on fuel you already paid tax on at the pump.

Jurisdiction miles from ELD and GPS data

Most fleets today build jurisdiction miles from ELD or telematics location data rather than from paper trip sheets. The ELD records the truck's position at regular intervals and on duty status changes, and the provider's software assigns miles to each state or province between points. Done right, it is accurate and nearly hands-off. Done carelessly, it produces confident-looking reports with holes in them.

What IFTA expects from distance records

Whatever the source, auditors expect distance records that can support the return at the vehicle level, typically including trip dates, origin and destination, routes, beginning and ending odometer or hub readings, total trip miles, miles by jurisdiction, and the unit number. GPS-based systems can satisfy this when the underlying data is retained and complete. Confirm with your base jurisdiction what format it accepts.

Where ELD miles go wrong

• Unplugged or failed devices. A device that loses power or connection leaves a gap. The truck still drove those miles.
• Unassigned driving. Miles recorded while no driver was logged in may be missing from driver-based reports. They still count for IFTA.
• Vehicles without ELDs. Older engines or exempt vehicles that still qualify for IFTA need another distance source.
• Units swapped or renumbered. A device moved to another tractor without updating the unit assignment puts miles on the wrong vehicle.
• Personal conveyance and yard moves. These are still miles in a qualified vehicle and generally reportable. Do not filter them out of IFTA just because they are excluded from HOS.
• Mid-quarter provider changes. Switching ELD vendors without exporting full history creates a hole you will find at audit time.

Monthly mileage checks

• Compare each unit's GPS miles against odometer or engine readings for the month. Investigate large differences.
• List every IFTA-qualified unit in the fleet and confirm each one has miles. A unit with zero miles should be parked, sold or explained.
• Look for date gaps per unit, especially multi-day gaps.
• Spot-check a few trips for continuity: a truck cannot leave one state and appear in a non-adjacent one without miles in between.
• Make sure deadhead and bobtail miles are included, not just loaded dispatch miles from the TMS.

Fuel card imports and receipts

On the fuel side, the goal is simple: every taxable gallon purchased is captured once, assigned to the right unit and jurisdiction, and backed by a receipt or transaction record.

Fuel card data

Most fuel card programs provide transaction files with date, merchant name and location, gallons, fuel type, price and the unit or driver entered at the pump. Importing that file into your TMS or fuel tax software each week, rather than once a quarter, lets you catch problems while drivers still remember the stop. Common issues:

• Wrong unit numbers keyed at the pump, which puts fuel on a truck that did not buy it.
• Reefer fuel mixed with tractor fuel. Fuel for refrigeration units is generally not IFTA propulsion fuel. Use the card program's ability to separate it at the pump, and keep it off the IFTA fuel totals.
• Non-fuel lines such as DEF, oil or scale tickets counted as gallons.
• Duplicate imports when a file is loaded twice or a transaction appears in two files.

Purchases outside the card

Cash or personal-card fuel purchases need a receipt showing at least the date, seller name and address, gallons, fuel type, price or total, and the unit number. Without it, those gallons cannot be credited. Bulk fuel from your own yard tank needs its own records: tax-paid status of deliveries, and withdrawals by unit. Bulk fuel rules vary by jurisdiction, so confirm with your base jurisdiction.

Fuel checks

• Fuel purchased in a jurisdiction where the unit shows no miles that day usually means a wrong unit number or a mileage gap.
• Per-unit MPG far outside the fleet's normal range points to missing fuel, missing miles or misassigned transactions.
• Gallons on a single transaction above the unit's tank capacity indicate a keying or split-fill problem.

Reconciliation: a monthly rhythm, not a quarterly fire drill

The single biggest change that ends the IFTA scramble is reconciling monthly. By the time the quarter closes, two-thirds of the work is already done and the third month is fresh.

Monthly IFTA close checklist

1. Import fuel card transactions for the month and clear the exceptions list.
2. Enter cash receipts and bulk withdrawals, with images attached.
3. Pull jurisdiction miles by unit from the ELD or GPS system.
4. Confirm every qualified unit has miles and fuel, or a documented reason it does not.
5. Compare GPS miles to odometer readings per unit; investigate outliers.
6. Review per-unit MPG against the fleet's normal range.
7. Resolve unassigned driving and device gaps.
8. Lock the month and save the supporting reports.

At quarter-end, combine the three locked months, apply the current quarter's tax rates, review the return against prior quarters for unusual swings, and file. Save a copy of every supporting report exactly as it was when you filed.

Audit readiness and record retention

Base jurisdictions audit IFTA licensees, and an audit typically examines both the distance records behind your miles and the fuel records behind your credits. If records are missing or unreliable, the auditor may estimate your fleet's fuel economy or miles, and estimates rarely favor the carrier.

Retention

IFTA requires you to keep records supporting each return for four years from the return due date or the date it was filed, whichever is later. Other tax rules or your base jurisdiction may require more, so confirm with your accountant.

Audit-ready checklist

One practical warning: if you change ELD or fuel card providers, export and archive complete history before the old account closes. Four years is longer than many vendor relationships. It is also worth making sure these records are covered by your backup plan; our trucking data backups guide covers that.

Connecting the systems

Much of the manual effort around IFTA comes from systems that do not talk to each other. A cleaner setup looks like this:

• ELD or telematics jurisdiction miles flow automatically into the TMS or fuel tax software by unit.
• Fuel card transactions import on a schedule, with unit numbers validated against the fleet roster.
• The fleet roster lives in one place and drives both the ELD unit list and the fuel card unit list.
• Exceptions (unknown units, MPG outliers, mileage gaps) land on one list with an owner.
• The same fuel data feeds driver settlements for fuel advances and deductions, so the numbers agree everywhere. See our driver settlement accuracy guide.

How Strong Tower Consulting helps

Strong Tower Consulting is a technology and business consulting firm, not a tax preparer. We help carriers fix the data and systems behind IFTA so that whoever files the return, in-house or an outside service, works from accurate numbers. That means connecting ELD and fuel card feeds to your TMS, cleaning up the fleet roster, building monthly reconciliation reports and exception lists, and documenting the process so it survives staff turnover.

• ELD, EDI & Back-Office Integration: ELD mileage, fuel card imports and accounting connections.
• Reporting & Business Documents: reconciliation and exception reports for the monthly close.
• SQL Data Mining & Analytics: finding gaps, duplicates and outliers in mileage and fuel history.

Frequently asked questions